feat: implements Multi-index execution plan (#2280)

lib/src/ctx/context.rs

@@ -1,7 +1,7 @@
 use crate::ctx::canceller::Canceller;
 use crate::ctx::reason::Reason;
 use crate::dbs::Notification;
-use crate::idx::planner::executor::QueryExecutor;
+use crate::idx::planner::QueryPlanner;
 use crate::sql::value::Value;
 use channel::Sender;
 use std::borrow::Cow;
@@ -34,8 +34,8 @@ pub struct Context<'a> {
 	values: HashMap<Cow<'static, str>, Cow<'a, Value>>,
 	// Stores the notification channel if available
 	notifications: Option<Sender<Notification>>,
-	// An optional query executor
+	// An optional query planner
-	query_executors: Option<Arc<HashMap<String, QueryExecutor>>>,
+	query_planner: Option<&'a QueryPlanner<'a>>,
 }
 
 impl<'a> Default for Context<'a> {
@@ -64,7 +64,7 @@ impl<'a> Context<'a> {
 			deadline: None,
 			cancelled: Arc::new(AtomicBool::new(false)),
 			notifications: None,
-			query_executors: None,
+			query_planner: None,
 		}
 	}
 
@@ -76,7 +76,7 @@ impl<'a> Context<'a> {
 			deadline: parent.deadline,
 			cancelled: Arc::new(AtomicBool::new(false)),
 			notifications: parent.notifications.clone(),
-			query_executors: parent.query_executors.clone(),
+			query_planner: parent.query_planner,
 		}
 	}
 
@@ -118,9 +118,9 @@ impl<'a> Context<'a> {
 		self.notifications = chn.cloned()
 	}
 
-	/// Set the query executors
+	/// Set the query planner
-	pub(crate) fn set_query_executors(&mut self, executors: HashMap<String, QueryExecutor>) {
+	pub(crate) fn set_query_planner(&mut self, qp: &'a QueryPlanner) {
-		self.query_executors = Some(Arc::new(executors));
+		self.query_planner = Some(qp);
 	}
 
 	/// Get the timeout for this operation, if any. This is useful for
@@ -133,12 +133,8 @@ impl<'a> Context<'a> {
 		self.notifications.clone()
 	}
 
-	pub(crate) fn get_query_executor(&self, tb: &str) -> Option<&QueryExecutor> {
+	pub(crate) fn get_query_planner(&self) -> Option<&QueryPlanner> {
-		if let Some(qe) = &self.query_executors {
+		self.query_planner
-			qe.get(tb)
-		} else {
-			None
-		}
 	}
 
 	/// Check if the context is done. If it returns `None` the operation may

lib/src/dbs/distinct.rs

@@ -0,0 +1,99 @@
+use crate::ctx::Context;
+use crate::dbs::{Iterable, Processed};
+use crate::kvs::Key;
+use radix_trie::Trie;
+use std::default::Default;
+#[cfg(not(target_arch = "wasm32"))]
+use std::sync::Arc;
+#[cfg(not(target_arch = "wasm32"))]
+use tokio::sync::Mutex;
+
+// TODO: This is currently processed in memory. In the future is should be on disk (mmap?)
+type Distinct = Trie<Key, bool>;
+
+#[derive(Default)]
+pub(crate) struct SyncDistinct {
+	processed: Distinct,
+}
+
+impl SyncDistinct {
+	pub(super) fn new(ctx: &Context<'_>) -> Option<Self> {
+		if let Some(pla) = ctx.get_query_planner() {
+			if pla.requires_distinct() {
+				return Some(Self::default());
+			}
+		}
+		None
+	}
+
+	fn is_distinct(ctx: &Context<'_>, i: &Iterable) -> bool {
+		if let Iterable::Index(t, ir, _) = i {
+			if let Some(pla) = ctx.get_query_planner() {
+				if let Some(exe) = pla.get_query_executor(&t.0) {
+					return exe.is_distinct(*ir);
+				}
+			}
+		}
+		false
+	}
+
+	pub(super) fn requires_distinct<'a>(
+		ctx: &Context<'_>,
+		dis: Option<&'a mut SyncDistinct>,
+		i: &Iterable,
+	) -> Option<&'a mut SyncDistinct> {
+		if dis.is_some() && Self::is_distinct(ctx, i) {
+			dis
+		} else {
+			None
+		}
+	}
+
+	pub(super) fn check_already_processed(&mut self, pro: &Processed) -> bool {
+		if let Some(key) = pro.rid.as_ref().map(|rid| rid.to_vec()) {
+			if self.processed.get(&key).is_some() {
+				true
+			} else {
+				self.processed.insert(key, true);
+				false
+			}
+		} else {
+			false
+		}
+	}
+}
+
+#[cfg(not(target_arch = "wasm32"))]
+#[derive(Default, Clone)]
+pub(crate) struct AsyncDistinct {
+	processed: Arc<Mutex<SyncDistinct>>,
+}
+
+#[cfg(not(target_arch = "wasm32"))]
+impl AsyncDistinct {
+	pub(super) fn new(ctx: &Context<'_>) -> Option<Self> {
+		if let Some(pla) = ctx.get_query_planner() {
+			if pla.requires_distinct() {
+				return Some(Self::default());
+			}
+		}
+		None
+	}
+
+	pub(super) fn requires_distinct(
+		ctx: &Context<'_>,
+		dis: Option<&AsyncDistinct>,
+		i: &Iterable,
+	) -> Option<AsyncDistinct> {
+		if let Some(dis) = dis {
+			if SyncDistinct::is_distinct(ctx, i) {
+				return Some(dis.clone());
+			}
+		}
+		None
+	}
+
+	pub(super) async fn check_already_processed(&self, pro: &Processed) -> bool {
+		self.processed.lock().await.check_already_processed(pro)
+	}
+}

lib/src/dbs/explanation.rs

@@ -81,9 +81,9 @@ impl ExplainItem {
 					("thing-3", Value::Thing(t3.to_owned())),
 				],
 			},
-			Iterable::Index(t, p) => Self {
+			Iterable::Index(t, _, io) => Self {
 				name: "Iterate Index".into(),
-				details: vec![("table", Value::from(t.0.to_owned())), ("plan", p.explain())],
+				details: vec![("table", Value::from(t.0.to_owned())), ("plan", io.explain())],
 			},
 		}
 	}

lib/src/dbs/iterator.rs

@@ -1,13 +1,16 @@
 use crate::ctx::Canceller;
 use crate::ctx::Context;
+#[cfg(not(target_arch = "wasm32"))]
+use crate::dbs::distinct::AsyncDistinct;
+use crate::dbs::distinct::SyncDistinct;
 use crate::dbs::explanation::Explanation;
 use crate::dbs::Statement;
 use crate::dbs::{Options, Transaction};
-use crate::doc::CursorDoc;
 use crate::doc::Document;
 use crate::err::Error;
 use crate::idx::ft::docids::DocId;
-use crate::idx::planner::plan::Plan;
+use crate::idx::planner::executor::IteratorRef;
+use crate::idx::planner::plan::IndexOption;
 use crate::sql::array::Array;
 use crate::sql::edges::Edges;
 use crate::sql::field::Field;
@@ -29,7 +32,14 @@ pub(crate) enum Iterable {
 	Edges(Edges),
 	Mergeable(Thing, Value),
 	Relatable(Thing, Thing, Thing),
-	Index(Table, Plan),
+	Index(Table, IteratorRef, IndexOption),
+}
+
+pub(crate) struct Processed {
+	pub(crate) ir: Option<IteratorRef>,
+	pub(crate) rid: Option<Thing>,
+	pub(crate) doc_id: Option<DocId>,
+	pub(crate) val: Operable,
 }
 
 pub(crate) enum Operable {
@@ -55,6 +65,7 @@ pub(crate) struct Iterator {
 	// Iterator runtime error
 	error: Option<Error>,
 	// Iterator output results
+	// TODO: Should be stored on disk / (mmap?)
 	results: Vec<Value>,
 	// Iterator input values
 	entries: Vec<Iterable>,
@@ -261,10 +272,10 @@ impl Iterator {
 								_ => {
 									let x = vals.first();
 									let x = if let Some(alias) = alias {
-										let cur = CursorDoc::new(None, None, &x);
+										let cur = (&x).into();
 										alias.compute(ctx, opt, txn, Some(&cur)).await?
 									} else {
-										let cur = CursorDoc::new(None, None, &x);
+										let cur = (&x).into();
 										expr.compute(ctx, opt, txn, Some(&cur)).await?
 									};
 									obj.set(ctx, opt, txn, idiom.as_ref(), x).await?;
@@ -378,9 +389,13 @@ impl Iterator {
 	) -> Result<(), Error> {
 		// Prevent deep recursion
 		let opt = &opt.dive(4)?;
+		// If any iterator requires distinct, we new to create a global distinct instance
+		let mut distinct = SyncDistinct::new(ctx);
 		// Process all prepared values
 		for v in mem::take(&mut self.entries) {
-			v.iterate(ctx, opt, txn, stm, self).await?;
+			// Distinct is passed only for iterators that really requires it
+			let dis = SyncDistinct::requires_distinct(ctx, distinct.as_mut(), &v);
+			v.iterate(ctx, opt, txn, stm, self, dis).await?;
 		}
 		// Everything processed ok
 		Ok(())
@@ -401,15 +416,21 @@ impl Iterator {
 		match stm.parallel() {
 			// Run statements sequentially
 			false => {
+				// If any iterator requires distinct, we new to create a global distinct instance
+				let mut distinct = SyncDistinct::new(ctx);
 				// Process all prepared values
 				for v in mem::take(&mut self.entries) {
-					v.iterate(ctx, opt, txn, stm, self).await?;
+					// Distinct is passed only for iterators that really requires it
+					let dis = SyncDistinct::requires_distinct(ctx, distinct.as_mut(), &v);
+					v.iterate(ctx, opt, txn, stm, self, dis).await?;
 				}
 				// Everything processed ok
 				Ok(())
 			}
 			// Run statements in parallel
 			true => {
+				// If any iterator requires distinct, we new to create a global distinct instance
+				let distinct = AsyncDistinct::new(ctx);
 				// Create a new executor
 				let e = executor::Executor::new();
 				// Take all of the iterator values
@@ -422,7 +443,9 @@ impl Iterator {
 				let adocs = async {
 					// Process all prepared values
 					for v in vals {
-						e.spawn(v.channel(ctx, opt, txn, stm, chn.clone()))
+						// Distinct is passed only for iterators that really requires it
+						let dis = AsyncDistinct::requires_distinct(ctx, distinct.as_ref(), &v);
+						e.spawn(v.channel(ctx, opt, txn, stm, chn.clone(), dis))
 							// Ensure we detach the spawned task
 							.detach();
 					}
@@ -434,8 +457,8 @@ impl Iterator {
 				// Create an async closure for received values
 				let avals = async {
 					// Process all received values
-					while let Ok((k, d, v)) = docs.recv().await {
+					while let Ok(pro) = docs.recv().await {
-						e.spawn(Document::compute(ctx, opt, txn, stm, chn.clone(), k, d, v))
+						e.spawn(Document::compute(ctx, opt, txn, stm, chn.clone(), pro))
 							// Ensure we detach the spawned task
 							.detach();
 					}
@@ -464,29 +487,26 @@ impl Iterator {
 	}
 
 	/// Process a new record Thing and Value
-	#[allow(clippy::too_many_arguments)]
 	pub async fn process(
 		&mut self,
 		ctx: &Context<'_>,
 		opt: &Options,
 		txn: &Transaction,
 		stm: &Statement<'_>,
-		thg: Option<Thing>,
+		pro: Processed,
-		doc_id: Option<DocId>,
-		val: Operable,
 	) {
 		// Check current context
 		if ctx.is_done() {
 			return;
 		}
 		// Setup a new workable
-		let (val, ext) = match val {
+		let (val, ext) = match pro.val {
 			Operable::Value(v) => (v, Workable::Normal),
 			Operable::Mergeable(v, o) => (v, Workable::Insert(o)),
 			Operable::Relatable(f, v, w) => (v, Workable::Relate(f, w)),
 		};
 		// Setup a new document
-		let mut doc = Document::new(thg.as_ref(), doc_id, &val, ext);
+		let mut doc = Document::new(pro.ir, pro.rid.as_ref(), pro.doc_id, &val, ext);
 		// Process the document
 		let res = match stm {
 			Statement::Select(_) => doc.select(ctx, opt, txn, stm).await,

lib/src/dbs/mod.rs

@@ -3,6 +3,7 @@
 //! glue between the API and the response. In this module we use channels as a transport layer
 //! and executors to process the operations. This module also gives a `context` to the transaction.
 mod auth;
+mod distinct;
 mod executor;
 mod explanation;
 mod iterator;

lib/src/dbs/processor.rs

@@ -1,8 +1,11 @@
 use crate::ctx::Context;
-use crate::dbs::{Iterable, Iterator, Operable, Options, Statement, Transaction};
+#[cfg(not(target_arch = "wasm32"))]
+use crate::dbs::distinct::AsyncDistinct;
+use crate::dbs::distinct::SyncDistinct;
+use crate::dbs::{Iterable, Iterator, Operable, Options, Processed, Statement, Transaction};
 use crate::err::Error;
-use crate::idx::ft::docids::DocId;
+use crate::idx::planner::executor::IteratorRef;
-use crate::idx::planner::plan::Plan;
+use crate::idx::planner::plan::IndexOption;
 use crate::key::{graph, thing};
 use crate::sql::dir::Dir;
 use crate::sql::{Edges, Range, Table, Thing, Value};
@@ -18,8 +21,9 @@ impl Iterable {
 		txn: &Transaction,
 		stm: &Statement<'_>,
 		ite: &mut Iterator,
+		dis: Option<&mut SyncDistinct>,
 	) -> Result<(), Error> {
-		Processor::Iterator(ite).process_iterable(ctx, opt, txn, stm, self).await
+		Processor::Iterator(dis, ite).process_iterable(ctx, opt, txn, stm, self).await
 	}
 
 	#[cfg(not(target_arch = "wasm32"))]
@@ -29,37 +33,49 @@ impl Iterable {
 		opt: &Options,
 		txn: &Transaction,
 		stm: &Statement<'_>,
-		chn: Sender<(Option<Thing>, Option<DocId>, Operable)>,
+		chn: Sender<Processed>,
+		dis: Option<AsyncDistinct>,
 	) -> Result<(), Error> {
-		Processor::Channel(chn).process_iterable(ctx, opt, txn, stm, self).await
+		Processor::Channel(dis, chn).process_iterable(ctx, opt, txn, stm, self).await
 	}
 }
 
 enum Processor<'a> {
-	Iterator(&'a mut Iterator),
+	Iterator(Option<&'a mut SyncDistinct>, &'a mut Iterator),
 	#[cfg(not(target_arch = "wasm32"))]
-	Channel(Sender<(Option<Thing>, Option<DocId>, Operable)>),
+	Channel(Option<AsyncDistinct>, Sender<Processed>),
 }
 
 impl<'a> Processor<'a> {
-	#[allow(clippy::too_many_arguments)]
 	async fn process(
 		&mut self,
 		ctx: &Context<'_>,
 		opt: &Options,
 		txn: &Transaction,
 		stm: &Statement<'_>,
-		rid: Option<Thing>,
+		pro: Processed,
-		doc_id: Option<DocId>,
-		val: Operable,
 	) -> Result<(), Error> {
 		match self {
-			Processor::Iterator(ite) => {
+			Processor::Iterator(distinct, ite) => {
-				ite.process(ctx, opt, txn, stm, rid, doc_id, val).await;
+				let is_processed = if let Some(d) = distinct {
+					d.check_already_processed(&pro)
+				} else {
+					false
+				};
+				if !is_processed {
+					ite.process(ctx, opt, txn, stm, pro).await;
+				}
 			}
 			#[cfg(not(target_arch = "wasm32"))]
-			Processor::Channel(chn) => {
+			Processor::Channel(distinct, chn) => {
-				chn.send((rid, doc_id, val)).await?;
+				let is_processed = if let Some(d) = distinct {
+					d.check_already_processed(&pro).await
+				} else {
+					false
+				};
+				if !is_processed {
+					chn.send(pro).await?;
+				}
 			}
 		};
 		Ok(())
@@ -80,7 +96,9 @@ impl<'a> Processor<'a> {
 				Iterable::Table(v) => self.process_table(ctx, opt, txn, stm, v).await?,
 				Iterable::Range(v) => self.process_range(ctx, opt, txn, stm, v).await?,
 				Iterable::Edges(e) => self.process_edge(ctx, opt, txn, stm, e).await?,
-				Iterable::Index(t, p) => self.process_index(ctx, opt, txn, stm, t, p).await?,
+				Iterable::Index(t, ir, io) => {
+					self.process_index(ctx, opt, txn, stm, t, ir, io).await?
+				}
 				Iterable::Mergeable(v, o) => {
 					self.process_mergeable(ctx, opt, txn, stm, v, o).await?
 				}
@@ -101,9 +119,14 @@ impl<'a> Processor<'a> {
 		v: Value,
 	) -> Result<(), Error> {
 		// Pass the value through
-		let val = Operable::Value(v);
+		let pro = Processed {
+			ir: None,
+			rid: None,
+			doc_id: None,
+			val: Operable::Value(v),
+		};
 		// Process the document record
-		self.process(ctx, opt, txn, stm, None, None, val).await
+		self.process(ctx, opt, txn, stm, pro).await
 	}
 
 	async fn process_thing(
@@ -125,7 +148,13 @@ impl<'a> Processor<'a> {
 			None => Value::None,
 		});
 		// Process the document record
-		self.process(ctx, opt, txn, stm, Some(v), None, val).await?;
+		let pro = Processed {
+			ir: None,
+			rid: Some(v),
+			doc_id: None,
+			val,
+		};
+		self.process(ctx, opt, txn, stm, pro).await?;
 		// Everything ok
 		Ok(())
 	}
@@ -152,7 +181,13 @@ impl<'a> Processor<'a> {
 		// Create a new operable value
 		let val = Operable::Mergeable(x, o);
 		// Process the document record
-		self.process(ctx, opt, txn, stm, Some(v), None, val).await?;
+		let pro = Processed {
+			ir: None,
+			rid: Some(v),
+			doc_id: None,
+			val,
+		};
+		self.process(ctx, opt, txn, stm, pro).await?;
 		// Everything ok
 		Ok(())
 	}
@@ -181,7 +216,13 @@ impl<'a> Processor<'a> {
 		// Create a new operable value
 		let val = Operable::Relatable(f, x, w);
 		// Process the document record
-		self.process(ctx, opt, txn, stm, Some(v), None, val).await?;
+		let pro = Processed {
+			ir: None,
+			rid: Some(v),
+			doc_id: None,
+			val,
+		};
+		self.process(ctx, opt, txn, stm, pro).await?;
 		// Everything ok
 		Ok(())
 	}
@@ -242,7 +283,13 @@ impl<'a> Processor<'a> {
 					// Create a new operable value
 					let val = Operable::Value(val);
 					// Process the record
-					self.process(ctx, opt, txn, stm, Some(rid), None, val).await?;
+					let pro = Processed {
+						ir: None,
+						rid: Some(rid),
+						doc_id: None,
+						val,
+					};
+					self.process(ctx, opt, txn, stm, pro).await?;
 				}
 				continue;
 			}
@@ -325,7 +372,13 @@ impl<'a> Processor<'a> {
 					// Create a new operable value
 					let val = Operable::Value(val);
 					// Process the record
-					self.process(ctx, opt, txn, stm, Some(rid), None, val).await?;
+					let pro = Processed {
+						ir: None,
+						rid: Some(rid),
+						doc_id: None,
+						val,
+					};
+					self.process(ctx, opt, txn, stm, pro).await?;
 				}
 				continue;
 			}
@@ -465,7 +518,13 @@ impl<'a> Processor<'a> {
 							None => Value::None,
 						});
 						// Process the record
-						self.process(ctx, opt, txn, stm, Some(rid), None, val).await?;
+						let pro = Processed {
+							ir: None,
+							rid: Some(rid),
+							doc_id: None,
+							val,
+						};
+						self.process(ctx, opt, txn, stm, pro).await?;
 					}
 					continue;
 				}
@@ -476,6 +535,7 @@ impl<'a> Processor<'a> {
 		Ok(())
 	}
 
+	#[allow(clippy::too_many_arguments)]
 	async fn process_index(
 		&mut self,
 		ctx: &Context<'_>,
@@ -483,13 +543,14 @@ impl<'a> Processor<'a> {
 		txn: &Transaction,
 		stm: &Statement<'_>,
 		table: Table,
-		plan: Plan,
+		ir: IteratorRef,
+		io: IndexOption,
 	) -> Result<(), Error> {
 		// Check that the table exists
 		txn.lock().await.check_ns_db_tb(opt.ns(), opt.db(), &table.0, opt.strict).await?;
-		let exe = ctx.get_query_executor(&table.0);
+		if let Some(pla) = ctx.get_query_planner() {
-		if let Some(exe) = exe {
+			if let Some(exe) = pla.get_query_executor(&table.0) {
-			let mut iterator = plan.new_iterator(opt, txn, exe).await?;
+				let mut iterator = exe.new_iterator(opt, ir, io).await?;
 				let mut things = iterator.next_batch(txn, 1000).await?;
 				while !things.is_empty() {
 					// Check if the context is finished
@@ -518,18 +579,24 @@ impl<'a> Processor<'a> {
 							None => Value::None,
 						});
 						// Process the document record
-					self.process(ctx, opt, txn, stm, Some(rid), Some(doc_id), val).await?;
+						let pro = Processed {
+							ir: Some(ir),
+							rid: Some(rid),
+							doc_id: Some(doc_id),
+							val,
+						};
+						self.process(ctx, opt, txn, stm, pro).await?;
 					}
 
 					// Collect the next batch of ids
 					things = iterator.next_batch(txn, 1000).await?;
 				}
 				// Everything ok
-			Ok(())
+				return Ok(());
-		} else {
+			}
+		}
 		Err(Error::QueryNotExecutedDetail {
-				message: "The QueryExecutor has not been found.".to_string(),
+			message: "No QueryExecutor has not been found.".to_string(),
 		})
 	}
 }
-}

lib/src/doc/compute.rs

@@ -1,36 +1,31 @@
 use crate::ctx::Context;
-use crate::dbs::Options;
 use crate::dbs::Statement;
 use crate::dbs::Workable;
 use crate::dbs::{Operable, Transaction};
+use crate::dbs::{Options, Processed};
 use crate::doc::Document;
 use crate::err::Error;
-use crate::idx::ft::docids::DocId;
-use crate::sql::thing::Thing;
 use crate::sql::value::Value;
 use channel::Sender;
 
 impl<'a> Document<'a> {
 	#[allow(dead_code)]
-	#[allow(clippy::too_many_arguments)]
 	pub(crate) async fn compute(
 		ctx: &Context<'_>,
 		opt: &Options,
 		txn: &Transaction,
 		stm: &Statement<'_>,
 		chn: Sender<Result<Value, Error>>,
-		thg: Option<Thing>,
+		pro: Processed,
-		doc_id: Option<DocId>,
-		val: Operable,
 	) -> Result<(), Error> {
 		// Setup a new workable
-		let ins = match val {
+		let ins = match pro.val {
 			Operable::Value(v) => (v, Workable::Normal),
 			Operable::Mergeable(v, o) => (v, Workable::Insert(o)),
 			Operable::Relatable(f, v, w) => (v, Workable::Relate(f, w)),
 		};
 		// Setup a new document
-		let mut doc = Document::new(thg.as_ref(), doc_id, &ins.0, ins.1);
+		let mut doc = Document::new(pro.ir, pro.rid.as_ref(), pro.doc_id, &ins.0, ins.1);
 		// Process the statement
 		let res = match stm {
 			Statement::Select(_) => doc.select(ctx, opt, txn, stm).await,

lib/src/doc/document.rs

@@ -4,6 +4,7 @@ use crate::dbs::Transaction;
 use crate::dbs::Workable;
 use crate::err::Error;
 use crate::idx::ft::docids::DocId;
+use crate::idx::planner::executor::IteratorRef;
 use crate::sql::statements::define::DefineEventStatement;
 use crate::sql::statements::define::DefineFieldStatement;
 use crate::sql::statements::define::DefineIndexStatement;
@@ -23,14 +24,21 @@ pub(crate) struct Document<'a> {
 }
 
 pub struct CursorDoc<'a> {
+	pub(crate) ir: Option<IteratorRef>,
 	pub(crate) rid: Option<&'a Thing>,
 	pub(crate) doc: Cow<'a, Value>,
 	pub(crate) doc_id: Option<DocId>,
 }
 
 impl<'a> CursorDoc<'a> {
-	pub(crate) fn new(rid: Option<&'a Thing>, doc_id: Option<DocId>, doc: &'a Value) -> Self {
+	pub(crate) fn new(
+		ir: Option<IteratorRef>,
+		rid: Option<&'a Thing>,
+		doc_id: Option<DocId>,
+		doc: &'a Value,
+	) -> Self {
 		Self {
+			ir,
 			rid,
 			doc: Cow::Borrowed(doc),
 			doc_id,
@@ -38,6 +46,28 @@ impl<'a> CursorDoc<'a> {
 	}
 }
 
+impl<'a> From<&'a Value> for CursorDoc<'a> {
+	fn from(doc: &'a Value) -> Self {
+		Self {
+			ir: None,
+			rid: None,
+			doc: Cow::Borrowed(doc),
+			doc_id: None,
+		}
+	}
+}
+
+impl<'a> From<&'a mut Value> for CursorDoc<'a> {
+	fn from(doc: &'a mut Value) -> Self {
+		Self {
+			ir: None,
+			rid: None,
+			doc: Cow::Borrowed(doc),
+			doc_id: None,
+		}
+	}
+}
+
 impl<'a> Debug for Document<'a> {
 	fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
 		write!(f, "Document - id: <{:?}>", self.id)
@@ -52,6 +82,7 @@ impl<'a> From<&Document<'a>> for Vec<u8> {
 
 impl<'a> Document<'a> {
 	pub fn new(
+		ir: Option<IteratorRef>,
 		id: Option<&'a Thing>,
 		doc_id: Option<DocId>,
 		val: &'a Value,
@@ -60,8 +91,8 @@ impl<'a> Document<'a> {
 		Document {
 			id,
 			extras,
-			current: CursorDoc::new(id, doc_id, val),
+			current: CursorDoc::new(ir, id, doc_id, val),
-			initial: CursorDoc::new(id, doc_id, val),
+			initial: CursorDoc::new(ir, id, doc_id, val),
 		}
 	}
 }

lib/src/fnc/operate.rs

@@ -171,13 +171,25 @@ pub(crate) async fn matches(
 	ctx: &Context<'_>,
 	txn: &Transaction,
 	doc: Option<&CursorDoc<'_>>,
-	e: &Expression,
+	exp: &Expression,
 ) -> Result<Value, Error> {
 	if let Some(doc) = doc {
 		if let Some(thg) = doc.rid {
-			if let Some(exe) = ctx.get_query_executor(&thg.tb) {
+			if let Some(pla) = ctx.get_query_planner() {
-				// Check the matches
+				if let Some(exe) = pla.get_query_executor(&thg.tb) {
-				return exe.matches(txn, thg, e).await;
+					// If we find the expression in `pre_match`,
+					// it means that we are using an Iterator::Index
+					// and we are iterating over documents that already matches the expression.
+					if let Some(ir) = doc.ir {
+						if let Some(e) = exe.get_iterator_expression(ir) {
+							if e.eq(exp) {
+								return Ok(Value::Bool(true));
+							}
+						}
+					}
+					// Evaluate the matches
+					return exe.matches(txn, thg, exp).await;
+				}
 			}
 		}
 	}

lib/src/fnc/search.rs

@@ -2,54 +2,57 @@ use crate::ctx::Context;
 use crate::dbs::Transaction;
 use crate::doc::CursorDoc;
 use crate::err::Error;
-use crate::sql::Value;
+use crate::idx::planner::executor::QueryExecutor;
+use crate::sql::{Thing, Value};
+
+fn get_execution_context<'a>(
+	ctx: &'a Context<'_>,
+	txn: Option<&'a Transaction>,
+	doc: Option<&'a CursorDoc<'_>>,
+) -> Option<(&'a Transaction, &'a QueryExecutor, &'a CursorDoc<'a>, &'a Thing)> {
+	if let Some(txn) = txn {
+		if let Some(doc) = doc {
+			if let Some(thg) = doc.rid {
+				if let Some(pla) = ctx.get_query_planner() {
+					if let Some(exe) = pla.get_query_executor(&thg.tb) {
+						return Some((txn, exe, doc, thg));
+					}
+				}
+			}
+		}
+	}
+	None
+}
 
 pub async fn score(
 	(ctx, txn, doc): (&Context<'_>, Option<&Transaction>, Option<&CursorDoc<'_>>),
 	(match_ref,): (Value,),
 ) -> Result<Value, Error> {
-	if let Some(txn) = txn {
+	if let Some((txn, exe, doc, thg)) = get_execution_context(ctx, txn, doc) {
-		if let Some(doc) = doc {
+		exe.score(txn, &match_ref, thg, doc.doc_id).await
-			if let Some(thg) = doc.rid {
+	} else {
-				if let Some(exe) = ctx.get_query_executor(&thg.tb) {
-					return exe.score(txn, &match_ref, thg, doc.doc_id).await;
-				}
-			}
-		}
-	}
 		Ok(Value::None)
 	}
+}
 
 pub async fn highlight(
 	(ctx, txn, doc): (&Context<'_>, Option<&Transaction>, Option<&CursorDoc<'_>>),
 	(prefix, suffix, match_ref): (Value, Value, Value),
 ) -> Result<Value, Error> {
-	if let Some(txn) = txn {
+	if let Some((txn, exe, doc, thg)) = get_execution_context(ctx, txn, doc) {
-		if let Some(doc) = doc {
+		exe.highlight(txn, thg, prefix, suffix, &match_ref, doc.doc.as_ref()).await
-			if let Some(thg) = doc.rid {
+	} else {
-				if let Some(exe) = ctx.get_query_executor(&thg.tb) {
-					return exe
-						.highlight(txn, thg, prefix, suffix, &match_ref, doc.doc.as_ref())
-						.await;
-				}
-			}
-		}
-	}
 		Ok(Value::None)
 	}
+}
 
 pub async fn offsets(
 	(ctx, txn, doc): (&Context<'_>, Option<&Transaction>, Option<&CursorDoc<'_>>),
 	(match_ref,): (Value,),
 ) -> Result<Value, Error> {
-	if let Some(txn) = txn {
+	if let Some((txn, exe, _, thg)) = get_execution_context(ctx, txn, doc) {
-		if let Some(doc) = doc {
+		exe.offsets(txn, thg, &match_ref).await
-			if let Some(thg) = doc.rid {
+	} else {
-				if let Some(exe) = ctx.get_query_executor(&thg.tb) {
-					return exe.offsets(txn, thg, &match_ref).await;
-				}
-			}
-		}
-	}
 		Ok(Value::None)
 	}
+}

lib/src/idx/ft/mod.rs

@@ -17,7 +17,7 @@ use crate::idx::ft::highlighter::{Highlighter, Offseter};
 use crate::idx::ft::offsets::Offsets;
 use crate::idx::ft::postings::Postings;
 use crate::idx::ft::scorer::BM25Scorer;
-use crate::idx::ft::termdocs::TermDocs;
+use crate::idx::ft::termdocs::{TermDocs, TermsDocs};
 use crate::idx::ft::terms::{TermId, Terms};
 use crate::idx::{btree, IndexKeyBase, SerdeState};
 use crate::kvs::{Key, Transaction};
@@ -320,7 +320,7 @@ impl FtIndex {
 
 	pub(super) fn new_hits_iterator(
 		&self,
-		terms_docs: Arc<Vec<Option<(TermId, RoaringTreemap)>>>,
+		terms_docs: TermsDocs,
 	) -> Result<Option<HitsIterator>, Error> {
 		let mut hits: Option<RoaringTreemap> = None;
 		for opt_term_docs in terms_docs.iter() {
@@ -342,10 +342,7 @@ impl FtIndex {
 		Ok(None)
 	}
 
-	pub(super) fn new_scorer(
+	pub(super) fn new_scorer(&self, terms_docs: TermsDocs) -> Result<Option<BM25Scorer>, Error> {
-		&self,
-		terms_docs: Arc<Vec<Option<(TermId, RoaringTreemap)>>>,
-	) -> Result<Option<BM25Scorer>, Error> {
 		if let Some(bm25) = &self.bm25 {
 			return Ok(Some(BM25Scorer::new(
 				self.postings.clone(),

lib/src/idx/ft/scorer.rs

@@ -2,10 +2,9 @@ use crate::err::Error;
 use crate::idx::ft::docids::DocId;
 use crate::idx::ft::doclength::{DocLength, DocLengths};
 use crate::idx::ft::postings::{Postings, TermFrequency};
-use crate::idx::ft::terms::TermId;
+use crate::idx::ft::termdocs::TermsDocs;
 use crate::idx::ft::Bm25Params;
 use crate::kvs::Transaction;
-use roaring::RoaringTreemap;
 use std::sync::Arc;
 use tokio::sync::RwLock;
 
@@ -13,7 +12,7 @@ pub(super) type Score = f32;
 
 pub(crate) struct BM25Scorer {
 	postings: Arc<RwLock<Postings>>,
-	terms_docs: Arc<Vec<Option<(TermId, RoaringTreemap)>>>,
+	terms_docs: TermsDocs,
 	doc_lengths: Arc<RwLock<DocLengths>>,
 	average_doc_length: f32,
 	doc_count: f32,
@@ -23,7 +22,7 @@ pub(crate) struct BM25Scorer {
 impl BM25Scorer {
 	pub(super) fn new(
 		postings: Arc<RwLock<Postings>>,
-		terms_docs: Arc<Vec<Option<(TermId, RoaringTreemap)>>>,
+		terms_docs: TermsDocs,
 		doc_lengths: Arc<RwLock<DocLengths>>,
 		total_docs_length: u128,
 		doc_count: u64,

lib/src/idx/planner/executor.rs

@@ -6,25 +6,28 @@ use crate::idx::ft::scorer::BM25Scorer;
 use crate::idx::ft::termdocs::TermsDocs;
 use crate::idx::ft::terms::TermId;
 use crate::idx::ft::{FtIndex, MatchRef};
+use crate::idx::planner::iterators::{
+	MatchesThingIterator, NonUniqueEqualThingIterator, ThingIterator, UniqueEqualThingIterator,
+};
 use crate::idx::planner::plan::IndexOption;
 use crate::idx::planner::tree::IndexMap;
 use crate::idx::IndexKeyBase;
 use crate::kvs;
 use crate::kvs::Key;
 use crate::sql::index::Index;
-use crate::sql::{Expression, Table, Thing, Value};
+use crate::sql::{Expression, Operator, Table, Thing, Value};
-use roaring::RoaringTreemap;
 use std::collections::HashMap;
 use std::sync::Arc;
 use tokio::sync::RwLock;
 
+pub(crate) type IteratorRef = u16;
+
 pub(crate) struct QueryExecutor {
 	table: String,
-	pre_match_expression: Option<Expression>,
-	pre_match_entry: Option<FtEntry>,
 	ft_map: HashMap<String, FtIndex>,
 	mr_entries: HashMap<MatchRef, FtEntry>,
 	exp_entries: HashMap<Expression, FtEntry>,
+	iterators: Vec<Expression>,
 }
 
 impl QueryExecutor {
@@ -33,7 +36,6 @@ impl QueryExecutor {
 		txn: &Transaction,
 		table: &Table,
 		index_map: IndexMap,
-		pre_match_expression: Option<Expression>,
 	) -> Result<Self, Error> {
 		let mut run = txn.lock().await;
 
@@ -82,25 +84,27 @@ impl QueryExecutor {
 			}
 		}
 
-		let mut pre_match_entry = None;
-		if let Some(exp) = &pre_match_expression {
-			pre_match_entry = exp_entries.get(exp).cloned();
-		}
 		Ok(Self {
 			table: table.0.clone(),
-			pre_match_expression,
-			pre_match_entry,
 			ft_map,
 			mr_entries,
 			exp_entries,
+			iterators: Vec::new(),
 		})
 	}
 
-	pub(super) fn pre_match_terms_docs(&self) -> Option<TermsDocs> {
+	pub(super) fn add_iterator(&mut self, exp: Expression) -> IteratorRef {
-		if let Some(entry) = &self.pre_match_entry {
+		let ir = self.iterators.len();
-			return Some(entry.0.terms_docs.clone());
+		self.iterators.push(exp);
+		ir as IteratorRef
 	}
-		None
+
+	pub(crate) fn is_distinct(&self, ir: IteratorRef) -> bool {
+		(ir as usize) < self.iterators.len()
+	}
+
+	pub(crate) fn get_iterator_expression(&self, ir: IteratorRef) -> Option<&Expression> {
+		self.iterators.get(ir as usize)
 	}
 
 	fn get_match_ref(match_ref: &Value) -> Option<MatchRef> {
@@ -112,21 +116,68 @@ impl QueryExecutor {
 		}
 	}
 
+	pub(crate) async fn new_iterator(
+		&self,
+		opt: &Options,
+		ir: IteratorRef,
+		io: IndexOption,
+	) -> Result<ThingIterator, Error> {
+		match &io.ix().index {
+			Index::Idx => Self::new_index_iterator(opt, io),
+			Index::Uniq => Self::new_unique_index_iterator(opt, io),
+			Index::Search {
+				..
+			} => self.new_search_index_iterator(ir, io).await,
+		}
+	}
+
+	fn new_index_iterator(opt: &Options, io: IndexOption) -> Result<ThingIterator, Error> {
+		if io.op() == &Operator::Equal {
+			return Ok(ThingIterator::NonUniqueEqual(NonUniqueEqualThingIterator::new(
+				opt,
+				io.ix(),
+				io.value(),
+			)?));
+		}
+		Err(Error::BypassQueryPlanner)
+	}
+
+	fn new_unique_index_iterator(opt: &Options, io: IndexOption) -> Result<ThingIterator, Error> {
+		if io.op() == &Operator::Equal {
+			return Ok(ThingIterator::UniqueEqual(UniqueEqualThingIterator::new(
+				opt,
+				io.ix(),
+				io.value(),
+			)?));
+		}
+		Err(Error::BypassQueryPlanner)
+	}
+
+	async fn new_search_index_iterator(
+		&self,
+		ir: IteratorRef,
+		io: IndexOption,
+	) -> Result<ThingIterator, Error> {
+		if let Some(exp) = self.iterators.get(ir as usize) {
+			if let Operator::Matches(_) = io.op() {
+				let ixn = &io.ix().name.0;
+				if let Some(fti) = self.ft_map.get(ixn) {
+					if let Some(fte) = self.exp_entries.get(exp) {
+						let it = MatchesThingIterator::new(fti, fte.0.terms_docs.clone()).await?;
+						return Ok(ThingIterator::Matches(it));
+					}
+				}
+			}
+		}
+		Err(Error::BypassQueryPlanner)
+	}
+
 	pub(crate) async fn matches(
 		&self,
 		txn: &Transaction,
 		thg: &Thing,
 		exp: &Expression,
 	) -> Result<Value, Error> {
-		// If we find the expression in `pre_match_expression`,
-		// it means that we are using an Iterator::Index
-		// and we are iterating over document that already matches the expression.
-		if let Some(pme) = &self.pre_match_expression {
-			if pme.eq(exp) {
-				return Ok(Value::Bool(true));
-			}
-		}
-
 		// Otherwise, we look for the first possible index options, and evaluate the expression
 		// Does the record id match this executor's table?
 		if thg.tb.eq(&self.table) {
@@ -244,7 +295,7 @@ struct Inner {
 	index_option: IndexOption,
 	doc_ids: Arc<RwLock<DocIds>>,
 	terms: Vec<Option<TermId>>,
-	terms_docs: Arc<Vec<Option<(TermId, RoaringTreemap)>>>,
+	terms_docs: TermsDocs,
 	scorer: Option<BM25Scorer>,
 }
 

lib/src/idx/planner/iterators.rs

@@ -0,0 +1,126 @@
+use crate::dbs::{Options, Transaction};
+use crate::err::Error;
+use crate::idx::ft::docids::{DocId, NO_DOC_ID};
+use crate::idx::ft::termdocs::TermsDocs;
+use crate::idx::ft::{FtIndex, HitsIterator};
+use crate::key;
+use crate::kvs::Key;
+use crate::sql::statements::DefineIndexStatement;
+use crate::sql::{Array, Thing, Value};
+
+pub(crate) enum ThingIterator {
+	NonUniqueEqual(NonUniqueEqualThingIterator),
+	UniqueEqual(UniqueEqualThingIterator),
+	Matches(MatchesThingIterator),
+}
+
+impl ThingIterator {
+	pub(crate) async fn next_batch(
+		&mut self,
+		tx: &Transaction,
+		size: u32,
+	) -> Result<Vec<(Thing, DocId)>, Error> {
+		match self {
+			ThingIterator::NonUniqueEqual(i) => i.next_batch(tx, size).await,
+			ThingIterator::UniqueEqual(i) => i.next_batch(tx, size).await,
+			ThingIterator::Matches(i) => i.next_batch(tx, size).await,
+		}
+	}
+}
+
+pub(crate) struct NonUniqueEqualThingIterator {
+	beg: Vec<u8>,
+	end: Vec<u8>,
+}
+
+impl NonUniqueEqualThingIterator {
+	pub(super) fn new(
+		opt: &Options,
+		ix: &DefineIndexStatement,
+		v: &Value,
+	) -> Result<NonUniqueEqualThingIterator, Error> {
+		let v = Array::from(v.clone());
+		let (beg, end) =
+			key::index::Index::range_all_ids(opt.ns(), opt.db(), &ix.what, &ix.name, &v);
+		Ok(Self {
+			beg,
+			end,
+		})
+	}
+
+	async fn next_batch(
+		&mut self,
+		txn: &Transaction,
+		limit: u32,
+	) -> Result<Vec<(Thing, DocId)>, Error> {
+		let min = self.beg.clone();
+		let max = self.end.clone();
+		let res = txn.lock().await.scan(min..max, limit).await?;
+		if let Some((key, _)) = res.last() {
+			self.beg = key.clone();
+			self.beg.push(0x00);
+		}
+		let res = res.iter().map(|(_, val)| (val.into(), NO_DOC_ID)).collect();
+		Ok(res)
+	}
+}
+
+pub(crate) struct UniqueEqualThingIterator {
+	key: Option<Key>,
+}
+
+impl UniqueEqualThingIterator {
+	pub(super) fn new(opt: &Options, ix: &DefineIndexStatement, v: &Value) -> Result<Self, Error> {
+		let v = Array::from(v.clone());
+		let key = key::index::Index::new(opt.ns(), opt.db(), &ix.what, &ix.name, v, None).into();
+		Ok(Self {
+			key: Some(key),
+		})
+	}
+
+	async fn next_batch(
+		&mut self,
+		txn: &Transaction,
+		_limit: u32,
+	) -> Result<Vec<(Thing, DocId)>, Error> {
+		if let Some(key) = self.key.take() {
+			if let Some(val) = txn.lock().await.get(key).await? {
+				return Ok(vec![(val.into(), NO_DOC_ID)]);
+			}
+		}
+		Ok(vec![])
+	}
+}
+
+pub(crate) struct MatchesThingIterator {
+	hits: Option<HitsIterator>,
+}
+
+impl MatchesThingIterator {
+	pub(super) async fn new(fti: &FtIndex, terms_docs: TermsDocs) -> Result<Self, Error> {
+		let hits = fti.new_hits_iterator(terms_docs)?;
+		Ok(Self {
+			hits,
+		})
+	}
+
+	async fn next_batch(
+		&mut self,
+		txn: &Transaction,
+		mut limit: u32,
+	) -> Result<Vec<(Thing, DocId)>, Error> {
+		let mut res = vec![];
+		if let Some(hits) = &mut self.hits {
+			let mut run = txn.lock().await;
+			while limit > 0 {
+				if let Some(hit) = hits.next(&mut run).await? {
+					res.push(hit);
+				} else {
+					break;
+				}
+				limit -= 1;
+			}
+		}
+		Ok(res)
+	}
+}

lib/src/idx/planner/mod.rs

@@ -1,14 +1,15 @@
 pub(crate) mod executor;
+pub(crate) mod iterators;
 pub(crate) mod plan;
 mod tree;
 
 use crate::ctx::Context;
-use crate::dbs::{Iterable, Options, Transaction};
+use crate::dbs::{Iterable, Iterator, Options, Transaction};
 use crate::err::Error;
 use crate::idx::planner::executor::QueryExecutor;
 use crate::idx::planner::plan::{Plan, PlanBuilder};
-use crate::idx::planner::tree::{Node, Tree};
+use crate::idx::planner::tree::Tree;
-use crate::sql::{Cond, Operator, Table};
+use crate::sql::{Cond, Table};
 use std::collections::HashMap;
 
 pub(crate) struct QueryPlanner<'a> {
@@ -16,6 +17,7 @@ pub(crate) struct QueryPlanner<'a> {
 	cond: &'a Option<Cond>,
 	/// There is one executor per table
 	executors: HashMap<String, QueryExecutor>,
+	requires_distinct: bool,
 }
 
 impl<'a> QueryPlanner<'a> {
@@ -24,83 +26,57 @@ impl<'a> QueryPlanner<'a> {
 			opt,
 			cond,
 			executors: HashMap::default(),
+			requires_distinct: false,
 		}
 	}
 
-	pub(crate) async fn get_iterable(
+	pub(crate) async fn add_iterables(
 		&mut self,
 		ctx: &Context<'_>,
 		txn: &Transaction,
 		t: Table,
-	) -> Result<Iterable, Error> {
+		it: &mut Iterator,
+	) -> Result<(), Error> {
 		let res = Tree::build(ctx, self.opt, txn, &t, self.cond).await?;
 		if let Some((node, im)) = res {
-			if let Some(plan) = AllAndStrategy::build(&node)? {
+			let mut exe = QueryExecutor::new(self.opt, txn, &t, im).await?;
-				let e = QueryExecutor::new(self.opt, txn, &t, im, Some(plan.e.clone())).await?;
+			let ok = match PlanBuilder::build(node) {
-				self.executors.insert(t.0.clone(), e);
+				Ok(plan) => match plan {
-				return Ok(Iterable::Index(t, plan));
+					Plan::SingleIndex(exp, io) => {
+						let ir = exe.add_iterator(exp);
+						it.ingest(Iterable::Index(t.clone(), ir, io));
+						true
 					}
-			let e = QueryExecutor::new(self.opt, txn, &t, im, None).await?;
+					Plan::MultiIndex(v) => {
-			self.executors.insert(t.0.clone(), e);
+						for (exp, io) in v {
+							let ir = exe.add_iterator(exp);
+							it.ingest(Iterable::Index(t.clone(), ir, io));
+							self.requires_distinct = true;
 						}
-		Ok(Iterable::Table(t))
+						true
 					}
-
-	pub(crate) fn finish(self) -> Option<HashMap<String, QueryExecutor>> {
-		if self.executors.is_empty() {
-			None
-		} else {
-			Some(self.executors)
-		}
-	}
-}
-
-struct AllAndStrategy {
-	b: PlanBuilder,
-}
-
-/// Successful if every boolean operators are AND
-/// and there is at least one condition covered by an index
-impl AllAndStrategy {
-	fn build(node: &Node) -> Result<Option<Plan>, Error> {
-		let mut s = AllAndStrategy {
-			b: PlanBuilder::default(),
-		};
-		match s.eval_node(node) {
-			Ok(_) => match s.b.build() {
-				Ok(p) => Ok(Some(p)),
-				Err(Error::BypassQueryPlanner) => Ok(None),
-				Err(e) => Err(e),
 				},
-			Err(Error::BypassQueryPlanner) => Ok(None),
+				Err(Error::BypassQueryPlanner) => false,
-			Err(e) => Err(e),
+				Err(e) => return Err(e),
+			};
+			self.executors.insert(t.0.clone(), exe);
+			if ok {
+				return Ok(());
 			}
 		}
-
+		it.ingest(Iterable::Table(t));
-	fn eval_node(&mut self, node: &Node) -> Result<(), Error> {
-		match node {
-			Node::Expression {
-				io: index_option,
-				left,
-				right,
-				exp: expression,
-			} => {
-				if let Some(io) = index_option {
-					self.b.add_index_option(expression.clone(), io.clone());
-				}
-				self.eval_expression(left, right, expression.operator())
-			}
-			Node::Unsupported => Err(Error::BypassQueryPlanner),
-			_ => Ok(()),
-		}
-	}
-
-	fn eval_expression(&mut self, left: &Node, right: &Node, op: &Operator) -> Result<(), Error> {
-		if op.eq(&Operator::Or) {
-			return Err(Error::BypassQueryPlanner);
-		}
-		self.eval_node(left)?;
-		self.eval_node(right)?;
 		Ok(())
 	}
+
+	pub(crate) fn has_executors(&self) -> bool {
+		!self.executors.is_empty()
+	}
+
+	pub(crate) fn get_query_executor(&self, tb: &str) -> Option<&QueryExecutor> {
+		self.executors.get(tb)
+	}
+
+	pub(crate) fn requires_distinct(&self) -> bool {
+		self.requires_distinct
+	}
 }

lib/src/idx/planner/plan.rs

@@ -1,74 +1,100 @@
-use crate::dbs::{Options, Transaction};
 use crate::err::Error;
-use crate::idx::btree::store::BTreeStoreType;
+use crate::idx::ft::MatchRef;
-use crate::idx::ft::docids::{DocId, NO_DOC_ID};
+use crate::idx::planner::tree::Node;
-use crate::idx::ft::termdocs::TermsDocs;
-use crate::idx::ft::{FtIndex, HitsIterator, MatchRef};
-use crate::idx::planner::executor::QueryExecutor;
-use crate::idx::IndexKeyBase;
-use crate::key;
-use crate::kvs::Key;
-use crate::sql::index::Index;
-use crate::sql::scoring::Scoring;
 use crate::sql::statements::DefineIndexStatement;
-use crate::sql::{Array, Expression, Ident, Idiom, Object, Operator, Thing, Value};
+use crate::sql::Object;
+use crate::sql::{Expression, Idiom, Operator, Value};
 use std::collections::HashMap;
 use std::hash::Hash;
 use std::sync::Arc;
 
-#[derive(Default)]
 pub(super) struct PlanBuilder {
 	indexes: Vec<(Expression, IndexOption)>,
+	all_and: bool,
+	all_exp_with_index: bool,
 }
 
 impl PlanBuilder {
-	pub(super) fn add_index_option(&mut self, e: Expression, i: IndexOption) {
+	pub(super) fn build(root: Node) -> Result<Plan, Error> {
-		self.indexes.push((e, i));
+		let mut b = PlanBuilder {
+			indexes: Vec::new(),
+			all_and: true,
+			all_exp_with_index: true,
+		};
+		// Browse the AST and collect information
+		b.eval_node(root)?;
+		// If we didn't found any index, we're done with no index plan
+		if b.indexes.is_empty() {
+			return Err(Error::BypassQueryPlanner);
+		}
+		// If every boolean operator are AND then we can use the single index plan
+		if b.all_and {
+			if let Some((e, i)) = b.indexes.pop() {
+				return Ok(Plan::SingleIndex(e, i));
+			}
+		}
+		// If every expression is backed by an index with can use the MultiIndex plan
+		if b.all_exp_with_index {
+			return Ok(Plan::MultiIndex(b.indexes));
 		}
-
-	pub(super) fn build(mut self) -> Result<Plan, Error> {
-		// TODO select the best option if there are several (cost based)
-		if let Some((e, i)) = self.indexes.pop() {
-			Ok(Plan::new(e, i))
-		} else {
 		Err(Error::BypassQueryPlanner)
 	}
+
+	fn eval_node(&mut self, node: Node) -> Result<(), Error> {
+		match node {
+			Node::Expression {
+				io,
+				left,
+				right,
+				exp,
+			} => {
+				if self.all_and && Operator::Or.eq(exp.operator()) {
+					self.all_and = false;
+				}
+				let is_bool = self.check_boolean_operator(exp.operator());
+				if let Some(io) = io {
+					self.add_index_option(exp, io);
+				} else if self.all_exp_with_index && !is_bool {
+					self.all_exp_with_index = false;
+				}
+				self.eval_expression(*left, *right)
+			}
+			Node::Unsupported => Err(Error::BypassQueryPlanner),
+			_ => Ok(()),
 		}
 	}
 
-pub(crate) struct Plan {
+	fn check_boolean_operator(&mut self, op: &Operator) -> bool {
-	pub(super) e: Expression,
+		match op {
-	pub(super) i: IndexOption,
+			Operator::Neg | Operator::Or => {
+				if self.all_and {
+					self.all_and = false;
 				}
-
+				true
-impl Plan {
+			}
-	pub(super) fn new(e: Expression, i: IndexOption) -> Self {
+			Operator::And => true,
-		Self {
+			_ => false,
-			e,
-			i,
 		}
 	}
 
-	pub(crate) async fn new_iterator(
+	fn eval_expression(&mut self, left: Node, right: Node) -> Result<(), Error> {
-		&self,
+		self.eval_node(left)?;
-		opt: &Options,
+		self.eval_node(right)?;
-		txn: &Transaction,
+		Ok(())
-		exe: &QueryExecutor,
-	) -> Result<ThingIterator, Error> {
-		self.i.new_iterator(opt, txn, exe).await
 	}
 
-	pub(crate) fn explain(&self) -> Value {
+	fn add_index_option(&mut self, e: Expression, i: IndexOption) {
-		Value::Object(Object::from(HashMap::from([
+		self.indexes.push((e, i));
-			("index", Value::from(self.i.ix().name.0.to_owned())),
-			("operator", Value::from(self.i.op().to_string())),
-			("value", self.i.value().clone()),
-		])))
 	}
 }
 
+pub(super) enum Plan {
+	SingleIndex(Expression, IndexOption),
+	MultiIndex(Vec<(Expression, IndexOption)>),
+}
+
 #[derive(Debug, Clone, Eq, PartialEq, Hash)]
-pub(super) struct IndexOption(Arc<Inner>);
+pub(crate) struct IndexOption(Arc<Inner>);
 
 #[derive(Debug, Eq, PartialEq, Hash)]
 pub(super) struct Inner {
@@ -123,193 +149,12 @@ impl IndexOption {
 		self.0.mr.as_ref()
 	}
 
-	async fn new_iterator(
+	pub(crate) fn explain(&self) -> Value {
-		&self,
+		Value::Object(Object::from(HashMap::from([
-		opt: &Options,
+			("index", Value::from(self.ix().name.0.to_owned())),
-		txn: &Transaction,
+			("operator", Value::from(self.op().to_string())),
-		exe: &QueryExecutor,
+			("value", self.value().clone()),
-	) -> Result<ThingIterator, Error> {
+		])))
-		match &self.ix().index {
-			Index::Idx => {
-				if self.op() == &Operator::Equal {
-					return Ok(ThingIterator::NonUniqueEqual(NonUniqueEqualThingIterator::new(
-						opt,
-						self.ix(),
-						self.value(),
-					)?));
-				}
-			}
-			Index::Uniq => {
-				if self.op() == &Operator::Equal {
-					return Ok(ThingIterator::UniqueEqual(UniqueEqualThingIterator::new(
-						opt,
-						self.ix(),
-						self.value(),
-					)?));
-				}
-			}
-			Index::Search {
-				az,
-				hl,
-				sc,
-				order,
-			} => {
-				if let Operator::Matches(_) = self.op() {
-					let td = exe.pre_match_terms_docs();
-					return Ok(ThingIterator::Matches(
-						MatchesThingIterator::new(opt, txn, self.ix(), az, *hl, sc, *order, td)
-							.await?,
-					));
-				}
-			}
-		}
-		Err(Error::BypassQueryPlanner)
-	}
-}
-
-pub(crate) enum ThingIterator {
-	NonUniqueEqual(NonUniqueEqualThingIterator),
-	UniqueEqual(UniqueEqualThingIterator),
-	Matches(MatchesThingIterator),
-}
-
-impl ThingIterator {
-	pub(crate) async fn next_batch(
-		&mut self,
-		tx: &Transaction,
-		size: u32,
-	) -> Result<Vec<(Thing, DocId)>, Error> {
-		match self {
-			ThingIterator::NonUniqueEqual(i) => i.next_batch(tx, size).await,
-			ThingIterator::UniqueEqual(i) => i.next_batch(tx, size).await,
-			ThingIterator::Matches(i) => i.next_batch(tx, size).await,
-		}
-	}
-}
-
-pub(crate) struct NonUniqueEqualThingIterator {
-	beg: Vec<u8>,
-	end: Vec<u8>,
-}
-
-impl NonUniqueEqualThingIterator {
-	fn new(
-		opt: &Options,
-		ix: &DefineIndexStatement,
-		v: &Value,
-	) -> Result<NonUniqueEqualThingIterator, Error> {
-		let v = Array::from(v.clone());
-		let (beg, end) =
-			key::index::Index::range_all_ids(opt.ns(), opt.db(), &ix.what, &ix.name, &v);
-		Ok(Self {
-			beg,
-			end,
-		})
-	}
-
-	async fn next_batch(
-		&mut self,
-		txn: &Transaction,
-		limit: u32,
-	) -> Result<Vec<(Thing, DocId)>, Error> {
-		let min = self.beg.clone();
-		let max = self.end.clone();
-		let res = txn.lock().await.scan(min..max, limit).await?;
-		if let Some((key, _)) = res.last() {
-			self.beg = key.clone();
-			self.beg.push(0x00);
-		}
-		let res = res.iter().map(|(_, val)| (val.into(), NO_DOC_ID)).collect();
-		Ok(res)
-	}
-}
-
-pub(crate) struct UniqueEqualThingIterator {
-	key: Option<Key>,
-}
-
-impl UniqueEqualThingIterator {
-	fn new(opt: &Options, ix: &DefineIndexStatement, v: &Value) -> Result<Self, Error> {
-		let v = Array::from(v.clone());
-		let key = key::index::Index::new(opt.ns(), opt.db(), &ix.what, &ix.name, v, None).into();
-		Ok(Self {
-			key: Some(key),
-		})
-	}
-
-	async fn next_batch(
-		&mut self,
-		txn: &Transaction,
-		_limit: u32,
-	) -> Result<Vec<(Thing, DocId)>, Error> {
-		if let Some(key) = self.key.take() {
-			if let Some(val) = txn.lock().await.get(key).await? {
-				return Ok(vec![(val.into(), NO_DOC_ID)]);
-			}
-		}
-		Ok(vec![])
-	}
-}
-
-pub(crate) struct MatchesThingIterator {
-	hits: Option<HitsIterator>,
-}
-
-impl MatchesThingIterator {
-	#[allow(clippy::too_many_arguments)]
-	async fn new(
-		opt: &Options,
-		txn: &Transaction,
-		ix: &DefineIndexStatement,
-		az: &Ident,
-		hl: bool,
-		sc: &Scoring,
-		order: u32,
-		terms_docs: Option<TermsDocs>,
-	) -> Result<Self, Error> {
-		let ikb = IndexKeyBase::new(opt, ix);
-		if let Scoring::Bm {
-			..
-		} = sc
-		{
-			let mut run = txn.lock().await;
-			let az = run.get_az(opt.ns(), opt.db(), az.as_str()).await?;
-			let fti = FtIndex::new(&mut run, az, ikb, order, sc, hl, BTreeStoreType::Read).await?;
-			if let Some(terms_docs) = terms_docs {
-				let hits = fti.new_hits_iterator(terms_docs)?;
-				Ok(Self {
-					hits,
-				})
-			} else {
-				Ok(Self {
-					hits: None,
-				})
-			}
-		} else {
-			Err(Error::FeatureNotYetImplemented {
-				feature: "Vector Search",
-			})
-		}
-	}
-
-	async fn next_batch(
-		&mut self,
-		txn: &Transaction,
-		mut limit: u32,
-	) -> Result<Vec<(Thing, DocId)>, Error> {
-		let mut res = vec![];
-		if let Some(hits) = &mut self.hits {
-			let mut run = txn.lock().await;
-			while limit > 0 {
-				if let Some(hit) = hits.next(&mut run).await? {
-					res.push(hit);
-				} else {
-					break;
-				}
-				limit -= 1;
-			}
-		}
-		Ok(res)
 	}
 }
 

lib/src/sql/field.rs

@@ -84,7 +84,7 @@ impl Fields {
 		if let Some(doc) = doc {
 			self.compute_value(ctx, opt, txn, doc, group).await
 		} else {
-			let doc = CursorDoc::new(None, None, &Value::None);
+			let doc = (&Value::None).into();
 			self.compute_value(ctx, opt, txn, &doc, group).await
 		}
 	}

lib/src/sql/statements/select.rs

@@ -97,7 +97,7 @@ impl SelectStatement {
 			let v = w.compute(ctx, opt, txn, doc).await?;
 			match v {
 				Value::Table(t) => {
-					i.ingest(planner.get_iterable(ctx, txn, t).await?);
+					planner.add_iterables(ctx, txn, t, &mut i).await?;
 				}
 				Value::Thing(v) => i.ingest(Iterable::Thing(v)),
 				Value::Range(v) => i.ingest(Iterable::Range(*v)),
@@ -128,9 +128,9 @@ impl SelectStatement {
 		// Assign the statement
 		let stm = Statement::from(self);
 		// Add query executors if any
-		if let Some(ex) = planner.finish() {
+		if planner.has_executors() {
 			let mut ctx = Context::new(ctx);
-			ctx.set_query_executors(ex);
+			ctx.set_query_planner(&planner);
 			// Output the results
 			i.output(&ctx, opt, txn, &stm).await
 		} else {

lib/src/sql/value/del.rs

@@ -1,6 +1,5 @@
 use crate::ctx::Context;
 use crate::dbs::{Options, Transaction};
-use crate::doc::CursorDoc;
 use crate::err::Error;
 use crate::exe::try_join_all_buffered;
 use crate::sql::array::Abolish;
@@ -119,7 +118,7 @@ impl Value {
 							// iterate in reverse, and call swap_remove
 							let mut m = HashSet::new();
 							for (i, v) in v.iter().enumerate() {
-								let cur = CursorDoc::new(None, None, v);
+								let cur = v.into();
 								if w.compute(ctx, opt, txn, Some(&cur)).await?.is_truthy() {
 									m.insert(i);
 								};
@@ -133,7 +132,7 @@ impl Value {
 								let mut p = Vec::new();
 								// Store the elements and positions to update
 								for (i, o) in v.iter_mut().enumerate() {
-									let cur = CursorDoc::new(None, None, o);
+									let cur = o.into();
 									if w.compute(ctx, opt, txn, Some(&cur)).await?.is_truthy() {
 										a.push(o.clone());
 										p.push(i);
@@ -157,7 +156,7 @@ impl Value {
 							_ => {
 								let path = path.next();
 								for v in v.iter_mut() {
-									let cur = CursorDoc::new(None, None, v);
+									let cur = v.into();
 									if w.compute(ctx, opt, txn, Some(&cur)).await?.is_truthy() {
 										v.del(ctx, opt, txn, path).await?;
 									}

lib/src/sql/value/fetch.rs

@@ -1,6 +1,5 @@
 use crate::ctx::Context;
 use crate::dbs::{Options, Transaction};
-use crate::doc::CursorDoc;
 use crate::err::Error;
 use crate::sql::edges::Edges;
 use crate::sql::field::{Field, Fields};
@@ -64,7 +63,7 @@ impl Value {
 					Part::Where(w) => {
 						let path = path.next();
 						for v in v.iter_mut() {
-							let cur = CursorDoc::new(None, None, v);
+							let cur = v.into();
 							if w.compute(ctx, opt, txn, Some(&cur)).await?.is_truthy() {
 								v.fetch(ctx, opt, txn, path).await?;
 							}

lib/src/sql/value/get.rs

@@ -123,8 +123,8 @@ impl Value {
 					Part::Where(w) => {
 						let mut a = Vec::new();
 						for v in v.iter() {
-							let cur = Some(CursorDoc::new(None, None, v));
+							let cur = v.into();
-							if w.compute(ctx, opt, txn, cur.as_ref()).await?.is_truthy() {
+							if w.compute(ctx, opt, txn, Some(&cur)).await?.is_truthy() {
 								a.push(v.clone());
 							}
 						}
@@ -382,7 +382,7 @@ mod tests {
 		let doc = Value::parse("{ name: 'Tobie', something: [{ age: 34 }, { age: 36 }] }");
 		let idi = Idiom::parse("test.something[WHERE age > 35]");
 		let val = Value::parse("{ test: <future> { { something: something } } }");
-		let cur = CursorDoc::new(None, None, &doc);
+		let cur = (&doc).into();
 		let res = val.get(&ctx, &opt, &txn, Some(&cur), &idi).await.unwrap();
 		assert_eq!(
 			res,

lib/src/sql/value/set.rs

@@ -1,6 +1,5 @@
 use crate::ctx::Context;
 use crate::dbs::{Options, Transaction};
-use crate::doc::CursorDoc;
 use crate::err::Error;
 use crate::exe::try_join_all_buffered;
 use crate::sql::part::Next;
@@ -92,7 +91,7 @@ impl Value {
 							let mut p = Vec::new();
 							// Store the elements and positions to update
 							for (i, o) in v.iter_mut().enumerate() {
-								let cur = CursorDoc::new(None, None, o);
+								let cur = o.into();
 								if w.compute(ctx, opt, txn, Some(&cur)).await?.is_truthy() {
 									a.push(o.clone());
 									p.push(i);
@@ -111,7 +110,7 @@ impl Value {
 						_ => {
 							let path = path.next();
 							for v in v.iter_mut() {
-								let cur = CursorDoc::new(None, None, v);
+								let cur = v.into();
 								if w.compute(ctx, opt, txn, Some(&cur)).await?.is_truthy() {
 									v.set(ctx, opt, txn, path, val.clone()).await?;
 								}

lib/tests/matches.rs

@@ -242,15 +242,19 @@ async fn select_where_matches_using_index_and_score() -> Result<(), Error> {
 #[tokio::test]
 async fn select_where_matches_without_using_index_and_score() -> Result<(), Error> {
 	let sql = r"
-		CREATE blog:1 SET title = 'the quick brown fox jumped over the lazy dog';
+		CREATE blog:1 SET title = 'the quick brown fox jumped over the lazy dog', label = 'test';
-		CREATE blog:2 SET title = 'the fast fox jumped over the lazy dog';
+		CREATE blog:2 SET title = 'the fast fox jumped over the lazy dog', label = 'test';
-		CREATE blog:3 SET title = 'the other animals sat there watching';
+		CREATE blog:3 SET title = 'the other animals sat there watching', label = 'test';
-		CREATE blog:4 SET title = 'the dog sat there and did nothing';
+		CREATE blog:4 SET title = 'the dog sat there and did nothing', label = 'test';
 		DEFINE ANALYZER simple TOKENIZERS blank,class;
 		DEFINE INDEX blog_title ON blog FIELDS title SEARCH ANALYZER simple BM25 HIGHLIGHTS;
 		LET $keywords = 'animals';
- 		SELECT id,search::score(1) AS score FROM blog WHERE (title @1@ $keywords AND id>0) OR (title @1@ $keywords AND id<99);
+ 		SELECT id,search::score(1) AS score FROM blog
-		SELECT id,search::score(1) + search::score(2) AS score FROM blog WHERE title @1@ 'dummy1' OR title @2@ 'dummy2';
+ 			WHERE (title @1@ $keywords AND label = 'test')
+ 			OR (title @1@ $keywords AND label = 'test');
+		SELECT id,search::score(1) + search::score(2) AS score FROM blog
+			WHERE (title @1@ 'dummy1' AND label = 'test')
+			OR (title @2@ 'dummy2' AND label = 'test');
 	";
 	let dbs = Datastore::new("memory").await?;
 	let ses = Session::for_kv().with_ns("test").with_db("test");

lib/tests/planner.rs

@@ -0,0 +1,109 @@
+mod parse;
+
+use parse::Parse;
+use surrealdb::dbs::Session;
+use surrealdb::err::Error;
+use surrealdb::kvs::Datastore;
+use surrealdb::sql::Value;
+
+async fn test_select_where_iterate_multi_index(parallel: bool) -> Result<(), Error> {
+	let parallel = if parallel {
+		"PARALLEL"
+	} else {
+		""
+	};
+	let sql = format!(
+		"
+		CREATE person:tobie SET name = 'Tobie', genre='m', company='SurrealDB';
+		CREATE person:jaime SET name = 'Jaime', genre='m', company='SurrealDB';
+		CREATE person:lizzie SET name = 'Lizzie', genre='f', company='SurrealDB';
+		CREATE person:neytiry SET name = 'Neytiri', genre='f', company='Metkayina';
+		DEFINE ANALYZER simple TOKENIZERS blank,class FILTERS lowercase;
+		DEFINE INDEX ft_company ON person FIELDS company SEARCH ANALYZER simple BM25;
+		DEFINE INDEX uniq_name ON TABLE person COLUMNS name UNIQUE;
+		DEFINE INDEX idx_genre ON TABLE person COLUMNS genre;
+		SELECT name FROM person WHERE name = 'Jaime' OR genre = 'm' OR company @@ 'surrealdb' {parallel};
+	    SELECT name FROM person WHERE name = 'Jaime' OR genre = 'm' OR company @@ 'surrealdb' {parallel} EXPLAIN FULL;"
+	);
+	let dbs = Datastore::new("memory").await?;
+	let ses = Session::for_kv().with_ns("test").with_db("test");
+	let res = &mut dbs.execute(&sql, &ses, None).await?;
+	assert_eq!(res.len(), 10);
+	//
+	for _ in 0..8 {
+		let _ = res.remove(0).result?;
+	}
+	//
+	let tmp = res.remove(0).result?;
+	let val = Value::parse(
+		"[
+			{
+				name: 'Jaime'
+			},
+            {
+				name: 'Tobie'
+			},
+			{
+				name: 'Lizzie'
+			}
+		]",
+	);
+	assert_eq!(format!("{:#}", tmp), format!("{:#}", val));
+	//
+	let tmp = res.remove(0).result?;
+	let val = Value::parse(
+		"[
+				{
+					detail: {
+						plan: {
+							index: 'uniq_name',
+							operator: '=',
+							value: 'Jaime'
+						},
+						table: 'person',
+					},
+					operation: 'Iterate Index'
+				},
+                {
+					detail: {
+						plan: {
+							index: 'idx_genre',
+							operator: '=',
+							value: 'm'
+						},
+						table: 'person',
+					},
+					operation: 'Iterate Index'
+				},
+				{
+					detail: {
+						plan: {
+							index: 'ft_company',
+							operator: '@@',
+							value: 'surrealdb'
+						},
+						table: 'person',
+					},
+					operation: 'Iterate Index'
+				},
+				{
+					detail: {
+						count: 3
+					},
+					operation: 'Fetch'
+				}
+			]",
+	);
+	assert_eq!(format!("{:#}", tmp), format!("{:#}", val));
+	Ok(())
+}
+
+#[tokio::test]
+async fn select_where_iterate_multi_index() -> Result<(), Error> {
+	test_select_where_iterate_multi_index(false).await
+}
+
+#[tokio::test]
+async fn select_where_iterate_multi_index_parallel() -> Result<(), Error> {
+	test_select_where_iterate_multi_index(true).await
+}