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executor: fix wrong result when index join on union scan. #8031

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merged 5 commits into from
Oct 25, 2018

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eurekaka
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@eurekaka eurekaka commented Oct 24, 2018

What problem does this PR solve?

If outer rows of index lookup join is larger than one batch, result of index lookup join is wrong.

What is changed and how it works?

Do not modify Plan of dataReaderBuilder directly, because it would impact next batch of outer rows, as well as other concurrent inner workers. Instead, build a local child builder to store the child plan.

Also, modify buildUnionScanFromReader to make it multi-threaded safe.

Check List

Tests

  • Unit test

Side effects

N/A

Related changes

N/A

Do not modify Plan of dataReaderBuilder directly, because it would
impact next batch of outer rows, as well as other concurrent inner
workers. Instead, build a local child builder to store the child plan.
@eurekaka eurekaka added type/bugfix This PR fixes a bug. sig/execution SIG execution labels Oct 24, 2018
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/run-all-tests

@@ -322,8 +322,6 @@ func (ow *outerWorker) pushToChan(ctx context.Context, task *lookUpJoinTask, dst
// buildTask builds a lookUpJoinTask and read outer rows.
// When err is not nil, task must not be nil to send the error to the main thread via task.
func (ow *outerWorker) buildTask(ctx context.Context) (*lookUpJoinTask, error) {
ow.executor.newFirstChunk()
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Why remove it? its not specified for union scan case?

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This should be irrelevant to this PR, will fix it. By the way, this line seems redundant, lines below would call ow.executor.newFirstChunk() again when declaring lookUpJoinTask, is there any special reason putting this line here?

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/run-all-tests

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@zz-jason @XuHuaiyu @winoros @lamxTyler PTAL

zz-jason
zz-jason previously approved these changes Oct 24, 2018
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LGTM

@zz-jason zz-jason dismissed their stale review October 24, 2018 10:51

need one more reviewer

@zz-jason zz-jason added the status/LGT1 Indicates that a PR has LGTM 1. label Oct 24, 2018
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rest lgtm

return b.buildUnionScanFromReader(reader, v)
us, err := b.buildUnionScanFromReader(reader, v)
if err != nil {
b.err = errors.Trace(err)
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Once the err is wrapped by errors.Trace(), it's no need to trace it any more now. Here just b.err = err is okay.

return nil, builder.err
e, err := builder.buildUnionScanFromReader(reader, v)
if err != nil {
return nil, errors.Trace(err)
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ditto

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@winoros comments addressed, PTAL.
@lamxTyler @XuHuaiyu PTAL. This fix seems error-prone, I need more reviewer...

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LGTM

@eurekaka eurekaka added status/LGT2 Indicates that a PR has LGTM 2. and removed status/LGT1 Indicates that a PR has LGTM 1. labels Oct 25, 2018
@eurekaka eurekaka merged commit d606b0d into pingcap:master Oct 25, 2018
@eurekaka eurekaka deleted the index_join_union_scan branch October 25, 2018 03:38
iamzhoug37 pushed a commit to iamzhoug37/tidb that referenced this pull request Oct 25, 2018
bugfix fixed pingcap#7518

expression: MySQL compatible current_user function (pingcap#7801)

plan: propagate constant over outer join (pingcap#7794)

- extract `outerCol = const` from join conditions and filter conditions,
  substitute `outerCol` in join conditions with `const`;
- extract `outerCol = innerCol` from join conditions, derive new join
  conditions based on this column equal condition and `outerCol` related
  expressions in join conditions and filter conditions;

util/timeutil: fix data race caused by forgetting set stats lease to 0 (pingcap#7901)

stats: handle ddl event for partition table (pingcap#7903)

plan: implement Operand and Pattern of cascades planner. (pingcap#7910)

planner: not convert to TableDual if empty range is derived from deferred constants (pingcap#7808)

plan: move projEliminate behind aggEliminate (pingcap#7909)

admin: fix admin check table bug of byte compare (pingcap#7887)

* admin: remove reflect deepEqual

stats: fix panic caused by empty histogram (pingcap#7912)

plan: fix panic caused by empty schema of LogicalTableDual (pingcap#7906)

* fix drop view if exist error (pingcap#7833)

executor: refine `explain analyze` (pingcap#7888)

executor: add an variable to compatible with MySQL insert for OGG (pingcap#7863)

expression: maintain `DeferredExpr` in aggressive constant folding. (pingcap#7915)

stats: fix histogram boundaries overflow error (pingcap#7883)

ddl:support the definition of `null` change to `not null` using `alter table` (pingcap#7771)

* ddl:support the definition of null change to not null using alter table

ddl: add check when create table with foreign key. (pingcap#7885)

* ddl: add check when create table with foreign key

planner: eliminate if null on non null column (pingcap#7924)

executor: fix a bug in point get (pingcap#7934)

planner, executor: refine ColumnPrune for LogicalUnionAll (pingcap#7930)

executor: fix panic when limit is too large (pingcap#7936)

ddl: add TiDB version to metrics (pingcap#7902)

stats: limit the length of sample values (pingcap#7931)

vendor: update tipb (pingcap#7893)

planner: support the Group and GroupExpr for the cascades planner (pingcap#7917)

store/tikv: log more information when other err occurs (pingcap#7948)

types: fix date time parse (pingcap#7933)

ddl: just print error message when ddl job is normal to calcel, to eliminate noisy log (pingcap#7875)

stats: update delta info for partition table (pingcap#7947)

explaintest: add explain test for partition pruning (pingcap#7505)

util: move disjoint set to util package (pingcap#7950)

util: add PreAlloc4Row and Insert for Chunk and List (pingcap#7916)

executor: add the slow log for commit (pingcap#7951)

expression: add builtin json_keys (pingcap#7776)

privilege: add USAGE in `show grants` for mysql compatibility (pingcap#7955)

ddl: fix invailid ddl job panic (pingcap#7940)

*: move ast.NewValueExpr to standalone parser_driver package (pingcap#7952)

Make the ast package get rid of the dependency of types.Datum

server: allow cors http request (pingcap#7939)

*: move `Statement` and `RecordSet` from ast to sqlexec package (pingcap#7970)

pr suggestion update

executor/aggfuncs: split unit tests to corresponding file (pingcap#7993)

store/tikv: fix typo (pingcap#7990)

executor, planner: clone proj schema for different children in buildProj4Union (pingcap#7999)

executor: let information_schema be the first database in ShowDatabases (pingcap#7938)

stats: use local feedback for partition table (pingcap#7963)

executor: add unit test for aggfuncs (pingcap#7966)

server: add log for binary execute statement (pingcap#7987)

admin: refine admin check decoder (pingcap#7862)

executor: improve wide table insert & update performance (pingcap#7935)

ddl: fix reassigned partition id in `truncate table` does not take effect (pingcap#7919)

fix reassigned partition id in truncate table does not take effect

add changelog for 2.1.0 rc4 (pingcap#8020)

*: make parser package dependency as small as possible (pingcap#7989)

parser: support `:=` in the `set` syntax (pingcap#8018)

According to MySQL document, `set` use the = assignment operator,
but the := assignment operator is also permitted

stats: garbage collect stats for partition table (pingcap#7962)

docs: add the proposal for the column pool (pingcap#7988)

expression: refine built-in func truncate to support uint arg (pingcap#8000)

stats: support show stats for partition table (pingcap#8023)

stats: update error rate for partition table (pingcap#8022)

stats: fix estimation for out of range point queries (pingcap#8015)

*: move parser to a separate repository (pingcap#8036)

executor: fix wrong result when index join on union scan. (pingcap#8031)

Do not modify Plan of dataReaderBuilder directly, because it would
impact next batch of outer rows, as well as other concurrent inner
workers. Instead, build a local child builder to store the child plan.

planner: fix a panic of a cached prepared statement with IndexScan (pingcap#8017)

*: fix the issue of executing DDL after executing SQL failure in txn (pingcap#8044)

* ddl, executor: fix the issue of executing DDL after executing SQL failure in txn

add unit test

remove debug info

add like evaluator case sensitive test

ddl, domain: make schema correct after canceling jobs (pingcap#7997)

unit test fix

code format

proposal: maintaining histograms in plan. (pingcap#7605)

support _tidb_rowid for table scan range (pingcap#8047)

var rename fix
alivxxx pushed a commit to alivxxx/tidb that referenced this pull request Jul 22, 2019
Do not modify Plan of dataReaderBuilder directly, because it would
impact next batch of outer rows, as well as other concurrent inner
workers. Instead, build a local child builder to store the child plan.
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4 participants