adapter: remove QGM code

ci/test/slt-fast.sh

@@ -17,7 +17,6 @@ tests=(
     test/sqllogictest/*.slt
     test/sqllogictest/attributes/*.slt \
     test/sqllogictest/explain/*.slt
-    test/sqllogictest/qgm/*.slt
     test/sqllogictest/autogenerated/*.slt
     test/sqllogictest/transform/*.slt
     # test/sqllogictest/sqlite/test/evidence/in1.test

doc/developer/101-query-compilation.md

@@ -85,29 +85,6 @@ Existing "fast paths" include:
 
 Currently, the optimization team is mostly concerned with the `HIR ⇒ MIR` and `MIR ⇒ MIR` stages.
 
-<!--
-# Future Pipeline
-
-[Diagram](https://docs.google.com/drawings/d/1Fil1-oYy3PkP3bD7WoZphW319Pj60cMAs2HcS9A21uo/edit)
-
-[Design doc](https://github.com/MaterializeInc/materialize/blob/main/doc/developer/design/20210707_qgm_sql_high_level_representation.md)
-
-* [`SQL ⇒ AST`](https://github.com/MaterializeInc/materialize/blob/main/src/sql-parser).
-    * Parsing the SQL query
-* `AST ⇒ QGM`.
-    * Name resolution.
-* `QGM ⇒ QGM`.
-    * Optimizing rewrites + decorrelation + more optimizing rewrites.
-* `QGM ⇒ MIR`.
-    * Lowering.
-* [`MIR ⇒ MIR`](https://github.com/MaterializeInc/materialize/blob/main/src/transform).
-    * Optimizations. What this looks like is to be determined.
-        * Some optimizations may become redundant after optimizing rewrites are added.
-        * Note that we may be able to eliminate the per-view/cross-view distinction by modifying MIR to have more than one starting point.
-* `MIR ⇒ LIR`.
-* `LIR ⇒ TDO`.
--->
-
 ## Testing
 
 ### Integration tests

src/adapter/src/coord/sequencer.rs

@@ -2677,23 +2677,19 @@ impl Coordinator {
 
         let optimizer_trace = match stage {
             Trace => OptimizerTrace::new(), // collect all trace entries
-            QueryGraph | OptimizedQueryGraph => OptimizerTrace::find(""), // don't collect anything
             stage => OptimizerTrace::find(stage.path()), // collect a trace entry only the selected stage
         };
 
         let (used_indexes, fast_path_plan) =
             optimizer_trace.collect_trace(|| -> Result<_, AdapterError> {
-                let raw_plan = raw_plan.clone(); // FIXME: remove `.clone()` once the QGM Model implements Clone.
                 let _span = tracing::span!(Level::INFO, "optimize").entered();
 
                 tracing::span!(Level::INFO, "raw").in_scope(|| {
                     trace_plan(&raw_plan);
                 });
 
                 // run optimization pipeline
-                let decorrelated_plan = raw_plan.optimize_and_lower(&OptimizerConfig {
-                    qgm_optimizations: session.vars().qgm_optimizations(),
-                })?;
+                let decorrelated_plan = raw_plan.optimize_and_lower(&OptimizerConfig {})?;
 
                 self.validate_timeline_context(decorrelated_plan.depends_on())?;
 
@@ -2739,63 +2735,16 @@ impl Coordinator {
                 Ok((used_indexes, fast_path_plan))
             })?;
 
-        let trace = if matches!(stage, QueryGraph | OptimizedQueryGraph) {
-            vec![] // FIXME: remove this case once the QGM Model implements Clone
-        } else {
-            optimizer_trace.drain_all(
-                format.clone(), // FIXME: remove `.clone()` once the QGM Model implements Clone
-                config.clone(), // FIXME: remove `.clone()` once the QGM Model implements Clone
-                self.catalog.for_session(session),
-                row_set_finishing.clone(), // FIXME: remove `.clone()` once the QGM Model implements Clone
-                used_indexes,
-                fast_path_plan,
-            )?
-        };
+        let trace = optimizer_trace.drain_all(
+            format,
+            config,
+            self.catalog.for_session(session),
+            row_set_finishing,
+            used_indexes,
+            fast_path_plan,
+        )?;
 
         let rows = match stage {
-            // QGM graphs are not collected in the trace at the moment as they
-            // do not implement Clone (see the TODOs in try_qgm_path.
-            // Once this is done the next two cases will be handled by the catch-all
-            // case at the end of this method.
-            QueryGraph => {
-                use mz_repr::explain_new::Explain;
-                // run partial pipeline
-                let mut model = mz_sql::query_model::Model::try_from(raw_plan)?;
-                // construct explanation context
-                let catalog = self.catalog.for_session(session);
-                let context = crate::explain_new::ExplainContext {
-                    config: &config,
-                    humanizer: &catalog,
-                    used_indexes: crate::explain_new::UsedIndexes::new(Default::default()),
-                    finishing: row_set_finishing,
-                    fast_path_plan: Default::default(),
-                };
-                // explain plan
-                let mut explainable = crate::explain_new::Explainable::new(&mut model);
-                let explanation_string = explainable.explain(&format, &config, &context)?;
-                // pack rows in result vector
-                vec![Row::pack_slice(&[Datum::from(&*explanation_string)])]
-            }
-            OptimizedQueryGraph => {
-                use mz_repr::explain_new::Explain;
-                // run partial pipeline
-                let mut model = mz_sql::query_model::Model::try_from(raw_plan)?;
-                model.optimize();
-                // construct explanation context
-                let catalog = self.catalog.for_session(session);
-                let context = crate::explain_new::ExplainContext {
-                    config: &config,
-                    humanizer: &catalog,
-                    used_indexes: crate::explain_new::UsedIndexes::new(Default::default()),
-                    finishing: row_set_finishing,
-                    fast_path_plan: Default::default(),
-                };
-                // explain plan
-                let mut explainable = crate::explain_new::Explainable::new(&mut model);
-                let explanation_string = explainable.explain(&format, &config, &context)?;
-                // pack rows in result vector
-                vec![Row::pack_slice(&[Datum::from(&*explanation_string)])]
-            }
             // For the `Trace` stage, return the entire trace as (time, path, plan) triples.
             Trace => {
                 let rows = trace
@@ -2904,9 +2853,7 @@ impl Coordinator {
             raw_plan, format, ..
         } = plan;
 
-        let decorrelated_plan = raw_plan.optimize_and_lower(&OptimizerConfig {
-            qgm_optimizations: session.vars().qgm_optimizations(),
-        })?;
+        let decorrelated_plan = raw_plan.optimize_and_lower(&OptimizerConfig {})?;
         let optimized_plan = self.view_optimizer.optimize(decorrelated_plan)?;
         let source_ids = optimized_plan.depends_on();
         let compute_instance = self.catalog.active_compute_instance(session)?;

src/adapter/src/error.rs

@@ -22,7 +22,6 @@ use mz_ore::str::StrExt;
 use mz_repr::explain_new::ExplainError;
 use mz_repr::NotNullViolation;
 use mz_sql::plan::PlanError;
-use mz_sql::query_model::QGMError;
 use mz_storage_client::controller::StorageError;
 use mz_transform::TransformError;
 
@@ -109,8 +108,6 @@ pub enum AdapterError {
     PlanError(PlanError),
     /// The named prepared statement already exists.
     PreparedStatementExists(String),
-    /// An error occurred in the QGM stage of the optimizer.
-    QGM(QGMError),
     /// The transaction is in read-only mode.
     ReadOnlyTransaction,
     /// The specified session parameter is read-only.
@@ -401,7 +398,6 @@ impl fmt::Display for AdapterError {
             AdapterError::PreparedStatementExists(name) => {
                 write!(f, "prepared statement {} already exists", name.quoted())
             }
-            AdapterError::QGM(e) => e.fmt(f),
             AdapterError::ReadOnlyTransaction => f.write_str("transaction in read-only mode"),
             AdapterError::ReadOnlyParameter(p) => {
                 write!(f, "parameter {} cannot be changed", p.name().quoted())
@@ -552,12 +548,6 @@ impl From<PlanError> for AdapterError {
     }
 }
 
-impl From<QGMError> for AdapterError {
-    fn from(e: QGMError) -> AdapterError {
-        AdapterError::QGM(e)
-    }
-}
-
 impl From<TransformError> for AdapterError {
     fn from(e: TransformError) -> AdapterError {
         AdapterError::Transform(e)

src/adapter/src/explain_new/mod.rs

@@ -33,7 +33,6 @@ pub(crate) mod hir;
 pub(crate) mod lir;
 pub(crate) mod mir;
 pub(crate) mod optimizer_trace;
-pub(crate) mod qgm;
 
 /// Newtype struct for wrapping types that should
 /// implement the [`mz_repr::explain_new::Explain`] trait.

src/adapter/src/session.rs

@@ -190,7 +190,7 @@ impl<T: TimestampManipulation> Session<T> {
                 let id = self.next_transaction_id;
                 self.next_transaction_id = self.next_transaction_id.wrapping_add(1);
                 self.transaction = TransactionStatus::InTransaction(Transaction {
-                    pcx: PlanContext::new(wall_time, self.vars.qgm_optimizations()),
+                    pcx: PlanContext::new(wall_time),
                     ops: TransactionOps::None,
                     write_lock_guard: None,
                     access,
@@ -224,7 +224,7 @@ impl<T: TimestampManipulation> Session<T> {
             let id = self.next_transaction_id;
             self.next_transaction_id = self.next_transaction_id.wrapping_add(1);
             let txn = Transaction {
-                pcx: PlanContext::new(wall_time, self.vars.qgm_optimizations()),
+                pcx: PlanContext::new(wall_time),
                 ops: TransactionOps::None,
                 write_lock_guard: None,
                 access: None,

src/adapter/src/session/vars.rs

@@ -129,13 +129,6 @@ const INTERVAL_STYLE: ServerVar<str> = ServerVar {
 
 const MZ_VERSION_NAME: &UncasedStr = UncasedStr::new("mz_version");
 
-const QGM_OPTIMIZATIONS: ServerVar<bool> = ServerVar {
-    name: UncasedStr::new("qgm_optimizations_experimental"),
-    value: &false,
-    description: "Enables optimizations based on a Query Graph Model (QGM) query representation.",
-    internal: false,
-};
-
 static DEFAULT_SEARCH_PATH: Lazy<[String; 1]> = Lazy::new(|| [DEFAULT_SCHEMA.to_owned()]);
 static SEARCH_PATH: Lazy<ServerVar<[String]>> = Lazy::new(|| ServerVar {
     name: UncasedStr::new("search_path"),
@@ -424,7 +417,6 @@ pub struct SessionVars {
     failpoints: ServerVar<str>,
     integer_datetimes: ServerVar<bool>,
     interval_style: ServerVar<str>,
-    qgm_optimizations: SessionVar<bool>,
     search_path: SessionVar<[String]>,
     server_version: ServerVar<str>,
     server_version_num: ServerVar<i32>,
@@ -455,7 +447,6 @@ impl SessionVars {
             failpoints: FAILPOINTS,
             integer_datetimes: INTEGER_DATETIMES,
             interval_style: INTERVAL_STYLE,
-            qgm_optimizations: SessionVar::new(&QGM_OPTIMIZATIONS),
             search_path: SessionVar::new(&SEARCH_PATH),
             server_version: SERVER_VERSION,
             server_version_num: SERVER_VERSION_NUM,
@@ -483,7 +474,7 @@ impl SessionVars {
     /// Returns an iterator over the configuration parameters and their current
     /// values for this session.
     pub fn iter(&self) -> impl Iterator<Item = &dyn Var> {
-        let vars: [&dyn Var; 25] = [
+        let vars: [&dyn Var; 24] = [
             &self.application_name,
             self.build_info,
             &self.client_encoding,
@@ -496,7 +487,6 @@ impl SessionVars {
             &self.failpoints,
             &self.integer_datetimes,
             &self.interval_style,
-            &self.qgm_optimizations,
             &self.search_path,
             &self.server_version,
             &self.server_version_num,
@@ -572,8 +562,6 @@ impl SessionVars {
             Ok(&self.interval_style)
         } else if name == MZ_VERSION_NAME {
             Ok(self.build_info)
-        } else if name == QGM_OPTIMIZATIONS.name {
-            Ok(&self.qgm_optimizations)
         } else if name == SEARCH_PATH.name {
             Ok(&self.search_path)
         } else if name == SERVER_VERSION.name {
@@ -690,8 +678,6 @@ impl SessionVars {
             } else {
                 Ok(())
             }
-        } else if name == QGM_OPTIMIZATIONS.name {
-            self.qgm_optimizations.set(value, local)
         } else if name == SEARCH_PATH.name {
             self.search_path.set(value, local)
         } else if name == SERVER_VERSION.name {
@@ -768,8 +754,6 @@ impl SessionVars {
             self.database.reset(local);
         } else if name == EXTRA_FLOAT_DIGITS.name {
             self.extra_float_digits.reset(local);
-        } else if name == QGM_OPTIMIZATIONS.name {
-            self.qgm_optimizations.reset(local);
         } else if name == SEARCH_PATH.name {
             self.search_path.reset(local);
         } else if name == SQL_SAFE_UPDATES.name {
@@ -822,7 +806,6 @@ impl SessionVars {
             failpoints: _,
             integer_datetimes: _,
             interval_style: _,
-            qgm_optimizations,
             search_path,
             server_version: _,
             server_version_num: _,
@@ -842,7 +825,6 @@ impl SessionVars {
         cluster_replica.end_transaction(action);
         database.end_transaction(action);
         extra_float_digits.end_transaction(action);
-        qgm_optimizations.end_transaction(action);
         search_path.end_transaction(action);
         sql_safe_updates.end_transaction(action);
         statement_timeout.end_transaction(action);
@@ -914,11 +896,6 @@ impl SessionVars {
         self.build_info.value()
     }
 
-    /// Returns the value of the `qgm_optimizations` configuration parameter.
-    pub fn qgm_optimizations(&self) -> bool {
-        *self.qgm_optimizations.value()
-    }
-
     /// Returns the value of the `search_path` configuration parameter.
     pub fn search_path(&self) -> Vec<&str> {
         self.search_path