From f20183da065b058315f5d2ed75cfb4859b1c8061 Mon Sep 17 00:00:00 2001 From: "vitess-bot[bot]" <108069721+vitess-bot[bot]@users.noreply.github.com> Date: Mon, 28 Oct 2024 16:53:35 +0530 Subject: [PATCH] Delegate Column Availability Checks to MySQL for Single-Route Queries (#17077) Signed-off-by: Harshit Gangal <harshit@planetscale.com> Signed-off-by: Andres Taylor <andres@planetscale.com> Co-authored-by: Andres Taylor <andres@planetscale.com> --- .../planbuilder/operators/plan_query.go | 33 ++++++++++++++++--- .../planbuilder/testdata/select_cases.json | 29 ++++++++++++++++ 2 files changed, 57 insertions(+), 5 deletions(-) diff --git a/go/vt/vtgate/planbuilder/operators/plan_query.go b/go/vt/vtgate/planbuilder/operators/plan_query.go index d5794a1bcf1..4a9f356d2bd 100644 --- a/go/vt/vtgate/planbuilder/operators/plan_query.go +++ b/go/vt/vtgate/planbuilder/operators/plan_query.go @@ -43,6 +43,7 @@ import ( "vitess.io/vitess/go/vt/sqlparser" "vitess.io/vitess/go/vt/vterrors" "vitess.io/vitess/go/vt/vtgate/planbuilder/plancontext" + "vitess.io/vitess/go/vt/vtgate/semantics" ) type ( @@ -71,13 +72,35 @@ func PlanQuery(ctx *plancontext.PlanningContext, stmt sqlparser.Statement) (resu checkValid(op) op = planQuery(ctx, op) - _, isRoute := op.(*Route) - if !isRoute && ctx.SemTable.NotSingleRouteErr != nil { - // If we got here, we don't have a single shard plan - return nil, ctx.SemTable.NotSingleRouteErr + if err := checkSingleRouteError(ctx, op); err != nil { + return nil, err } - return op, err + return op, nil +} + +// checkSingleRouteError checks if the query has a NotSingleRouteErr and more than one route, and returns an error if it does +func checkSingleRouteError(ctx *plancontext.PlanningContext, op Operator) error { + if ctx.SemTable.NotSingleRouteErr == nil { + return nil + } + routes := 0 + visitF := func(op Operator, _ semantics.TableSet, _ bool) (Operator, *ApplyResult) { + switch op.(type) { + case *Route: + routes++ + } + return op, NoRewrite + } + + // we'll walk the tree and count the number of routes + TopDown(op, TableID, visitF, stopAtRoute) + + if routes <= 1 { + return nil + } + + return ctx.SemTable.NotSingleRouteErr } func PanicHandler(err *error) { diff --git a/go/vt/vtgate/planbuilder/testdata/select_cases.json b/go/vt/vtgate/planbuilder/testdata/select_cases.json index bf1e1950760..cbe14c48b5a 100644 --- a/go/vt/vtgate/planbuilder/testdata/select_cases.json +++ b/go/vt/vtgate/planbuilder/testdata/select_cases.json @@ -65,6 +65,35 @@ ] } }, + { + "comment": "join on sharding column with limit - should be a simple scatter query and limit on top with non resolved columns", + "query": "select * from user u join user_metadata um on u.id = um.user_id where foo=41 limit 20", + "plan": { + "QueryType": "SELECT", + "Original": "select * from user u join user_metadata um on u.id = um.user_id where foo=41 limit 20", + "Instructions": { + "OperatorType": "Limit", + "Count": "20", + "Inputs": [ + { + "OperatorType": "Route", + "Variant": "Scatter", + "Keyspace": { + "Name": "user", + "Sharded": true + }, + "FieldQuery": "select * from `user` as u, user_metadata as um where 1 != 1", + "Query": "select * from `user` as u, user_metadata as um where foo = 41 and u.id = um.user_id limit 20", + "Table": "`user`, user_metadata" + } + ] + }, + "TablesUsed": [ + "user.user", + "user.user_metadata" + ] + } + }, { "comment": "select with timeout directive sets QueryTimeout in the route", "query": "select /*vt+ QUERY_TIMEOUT_MS=1000 */ * from user",