c21 opened a new pull request #32476: URL: https://github.com/apache/spark/pull/32476
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If you want to add or modify an error message, please read the guideline first: https://spark.apache.org/error-message-guidelines.html --> ### What changes were proposed in this pull request? <!-- Please clarify what changes you are proposing. The purpose of this section is to outline the changes and how this PR fixes the issue. If possible, please consider writing useful notes for better and faster reviews in your PR. See the examples below. 1. If you refactor some codes with changing classes, showing the class hierarchy will help reviewers. 2. If you fix some SQL features, you can provide some references of other DBMSes. 3. If there is design documentation, please add the link. 4. If there is a discussion in the mailing list, please add the link. --> This PR is to add code-gen support for LEFT OUTER / RIGHT OUTER sort merge join. Currently sort merge join only supports inner join type (https://github.com/apache/spark/blob/master/sql/core/src/main/scala/org/apache/spark/sql/execution/joins/SortMergeJoinExec.scala#L374 ). There's no fundamental reason why we cannot support code-gen for other join types. Here we add code-gen for LEFT OUTER / RIGHT OUTER join. Will submit followup PRs to add LEFT SEMI, LEFT ANTI and FULL OUTER code-gen separately. The change is to extend current sort merge join logic to work with LEFT OUTER and RIGHT OUTER (should work with LEFT SEMI/ANTI as well, but FULL OUTER join needs some other more code change). Replace left/right with streamed/buffered to make code extendable to other join types besides inner join. Example query: ``` val df1 = spark.range(10).select($"id".as("k1"), $"id".as("k3")) val df2 = spark.range(4).select($"id".as("k2"), $"id".as("k4")) df1.join(df2.hint("SHUFFLE_MERGE"), $"k1" === $"k2" && $"k3" + 1 < $"k4", "left_outer").explain("codegen") ``` Example generated code: ``` == Subtree 5 / 5 (maxMethodCodeSize:396; maxConstantPoolSize:159(0.24% used); numInnerClasses:0) == *(5) SortMergeJoin [k1#2L], [k2#8L], LeftOuter, ((k3#3L + 1) < k4#9L) :- *(2) Sort [k1#2L ASC NULLS FIRST], false, 0 : +- Exchange hashpartitioning(k1#2L, 5), ENSURE_REQUIREMENTS, [id=#26] : +- *(1) Project [id#0L AS k1#2L, id#0L AS k3#3L] : +- *(1) Range (0, 10, step=1, splits=2) +- *(4) Sort [k2#8L ASC NULLS FIRST], false, 0 +- Exchange hashpartitioning(k2#8L, 5), ENSURE_REQUIREMENTS, [id=#32] +- *(3) Project [id#6L AS k2#8L, id#6L AS k4#9L] +- *(3) Range (0, 4, step=1, splits=2) Generated code: /* 001 */ public Object generate(Object[] references) { /* 002 */ return new GeneratedIteratorForCodegenStage5(references); /* 003 */ } /* 004 */ /* 005 */ // codegenStageId=5 /* 006 */ final class GeneratedIteratorForCodegenStage5 extends org.apache.spark.sql.execution.BufferedRowIterator { /* 007 */ private Object[] references; /* 008 */ private scala.collection.Iterator[] inputs; /* 009 */ private scala.collection.Iterator smj_streamedInput_0; /* 010 */ private scala.collection.Iterator smj_bufferedInput_0; /* 011 */ private InternalRow smj_streamedRow_0; /* 012 */ private InternalRow smj_bufferedRow_0; /* 013 */ private long smj_value_2; /* 014 */ private org.apache.spark.sql.execution.ExternalAppendOnlyUnsafeRowArray smj_matches_0; /* 015 */ private long smj_value_3; /* 016 */ private org.apache.spark.sql.catalyst.expressions.codegen.UnsafeRowWriter[] smj_mutableStateArray_0 = new org.apache.spark.sql.catalyst.expressions.codegen.UnsafeRowWriter[1]; /* 017 */ /* 018 */ public GeneratedIteratorForCodegenStage5(Object[] references) { /* 019 */ this.references = references; /* 020 */ } /* 021 */ /* 022 */ public void init(int index, scala.collection.Iterator[] inputs) { /* 023 */ partitionIndex = index; /* 024 */ this.inputs = inputs; /* 025 */ smj_streamedInput_0 = inputs[0]; /* 026 */ smj_bufferedInput_0 = inputs[1]; /* 027 */ /* 028 */ smj_matches_0 = new org.apache.spark.sql.execution.ExternalAppendOnlyUnsafeRowArray(2147483632, 2147483647); /* 029 */ smj_mutableStateArray_0[0] = new org.apache.spark.sql.catalyst.expressions.codegen.UnsafeRowWriter(4, 0); /* 030 */ /* 031 */ } /* 032 */ /* 033 */ private boolean findNextJoinRows( /* 034 */ scala.collection.Iterator streamedIter, /* 035 */ scala.collection.Iterator bufferedIter) { /* 036 */ smj_streamedRow_0 = null; /* 037 */ int comp = 0; /* 038 */ while (smj_streamedRow_0 == null) { /* 039 */ if (!streamedIter.hasNext()) return false; /* 040 */ smj_streamedRow_0 = (InternalRow) streamedIter.next(); /* 041 */ long smj_value_0 = smj_streamedRow_0.getLong(0); /* 042 */ if (false) { /* 043 */ if (!smj_matches_0.isEmpty()) { /* 044 */ smj_matches_0.clear(); /* 045 */ } /* 046 */ return false; /* 047 */ /* 048 */ } /* 049 */ if (!smj_matches_0.isEmpty()) { /* 050 */ comp = 0; /* 051 */ if (comp == 0) { /* 052 */ comp = (smj_value_0 > smj_value_3 ? 1 : smj_value_0 < smj_value_3 ? -1 : 0); /* 053 */ } /* 054 */ /* 055 */ if (comp == 0) { /* 056 */ return true; /* 057 */ } /* 058 */ smj_matches_0.clear(); /* 059 */ } /* 060 */ /* 061 */ do { /* 062 */ if (smj_bufferedRow_0 == null) { /* 063 */ if (!bufferedIter.hasNext()) { /* 064 */ smj_value_3 = smj_value_0; /* 065 */ return !smj_matches_0.isEmpty(); /* 066 */ } /* 067 */ smj_bufferedRow_0 = (InternalRow) bufferedIter.next(); /* 068 */ long smj_value_1 = smj_bufferedRow_0.getLong(0); /* 069 */ if (false) { /* 070 */ smj_bufferedRow_0 = null; /* 071 */ continue; /* 072 */ } /* 073 */ smj_value_2 = smj_value_1; /* 074 */ } /* 075 */ /* 076 */ comp = 0; /* 077 */ if (comp == 0) { /* 078 */ comp = (smj_value_0 > smj_value_2 ? 1 : smj_value_0 < smj_value_2 ? -1 : 0); /* 079 */ } /* 080 */ /* 081 */ if (comp > 0) { /* 082 */ smj_bufferedRow_0 = null; /* 083 */ } else if (comp < 0) { /* 084 */ if (!smj_matches_0.isEmpty()) { /* 085 */ smj_value_3 = smj_value_0; /* 086 */ return true; /* 087 */ } else { /* 088 */ return false; /* 089 */ } /* 090 */ } else { /* 091 */ smj_matches_0.add((UnsafeRow) smj_bufferedRow_0); /* 092 */ smj_bufferedRow_0 = null; /* 093 */ } /* 094 */ } while (smj_streamedRow_0 != null); /* 095 */ } /* 096 */ return false; // unreachable /* 097 */ } /* 098 */ /* 099 */ protected void processNext() throws java.io.IOException { /* 100 */ while (smj_streamedInput_0.hasNext()) { /* 101 */ findNextJoinRows(smj_streamedInput_0, smj_bufferedInput_0); /* 102 */ long smj_value_4 = -1L; /* 103 */ long smj_value_5 = -1L; /* 104 */ boolean smj_loaded_0 = false; /* 105 */ smj_value_5 = smj_streamedRow_0.getLong(1); /* 106 */ scala.collection.Iterator<UnsafeRow> smj_iterator_0 = smj_matches_0.generateIterator(); /* 107 */ boolean smj_foundMatch_0 = false; /* 108 */ /* 109 */ // the last iteration of this loop is to emit an empty row if there is no matched rows. /* 110 */ while (smj_iterator_0.hasNext() || !smj_foundMatch_0) { /* 111 */ InternalRow smj_bufferedRow_1 = smj_iterator_0.hasNext() ? /* 112 */ (InternalRow) smj_iterator_0.next() : null; /* 113 */ boolean smj_isNull_5 = true; /* 114 */ long smj_value_9 = -1L; /* 115 */ if (smj_bufferedRow_1 != null) { /* 116 */ long smj_value_8 = smj_bufferedRow_1.getLong(1); /* 117 */ smj_isNull_5 = false; /* 118 */ smj_value_9 = smj_value_8; /* 119 */ } /* 120 */ if (smj_bufferedRow_1 != null) { /* 121 */ boolean smj_isNull_6 = true; /* 122 */ boolean smj_value_10 = false; /* 123 */ long smj_value_11 = -1L; /* 124 */ /* 125 */ smj_value_11 = smj_value_5 + 1L; /* 126 */ /* 127 */ if (!smj_isNull_5) { /* 128 */ smj_isNull_6 = false; // resultCode could change nullability. /* 129 */ smj_value_10 = smj_value_11 < smj_value_9; /* 130 */ /* 131 */ } /* 132 */ if (smj_isNull_6 || !smj_value_10) { /* 133 */ continue; /* 134 */ } /* 135 */ } /* 136 */ if (!smj_loaded_0) { /* 137 */ smj_loaded_0 = true; /* 138 */ smj_value_4 = smj_streamedRow_0.getLong(0); /* 139 */ } /* 140 */ boolean smj_isNull_3 = true; /* 141 */ long smj_value_7 = -1L; /* 142 */ if (smj_bufferedRow_1 != null) { /* 143 */ long smj_value_6 = smj_bufferedRow_1.getLong(0); /* 144 */ smj_isNull_3 = false; /* 145 */ smj_value_7 = smj_value_6; /* 146 */ } /* 147 */ smj_foundMatch_0 = true; /* 148 */ ((org.apache.spark.sql.execution.metric.SQLMetric) references[0] /* numOutputRows */).add(1); /* 149 */ /* 150 */ smj_mutableStateArray_0[0].reset(); /* 151 */ /* 152 */ smj_mutableStateArray_0[0].zeroOutNullBytes(); /* 153 */ /* 154 */ smj_mutableStateArray_0[0].write(0, smj_value_4); /* 155 */ /* 156 */ smj_mutableStateArray_0[0].write(1, smj_value_5); /* 157 */ /* 158 */ if (smj_isNull_3) { /* 159 */ smj_mutableStateArray_0[0].setNullAt(2); /* 160 */ } else { /* 161 */ smj_mutableStateArray_0[0].write(2, smj_value_7); /* 162 */ } /* 163 */ /* 164 */ if (smj_isNull_5) { /* 165 */ smj_mutableStateArray_0[0].setNullAt(3); /* 166 */ } else { /* 167 */ smj_mutableStateArray_0[0].write(3, smj_value_9); /* 168 */ } /* 169 */ append((smj_mutableStateArray_0[0].getRow()).copy()); /* 170 */ /* 171 */ } /* 172 */ if (shouldStop()) return; /* 173 */ } /* 174 */ ((org.apache.spark.sql.execution.joins.SortMergeJoinExec) references[1] /* plan */).cleanupResources(); /* 175 */ } /* 176 */ /* 177 */ } ``` ### Why are the changes needed? <!-- Please clarify why the changes are needed. For instance, 1. If you propose a new API, clarify the use case for a new API. 2. If you fix a bug, you can clarify why it is a bug. --> Improve query CPU performance. Example micro benchmark below showed 10% run-time improvement. ``` def sortMergeJoinWithDuplicates(): Unit = { val N = 2 << 20 codegenBenchmark("sort merge join with duplicates", N) { val df1 = spark.range(N) .selectExpr(s"(id * 15485863) % ${N*10} as k1", "id as k3") val df2 = spark.range(N) .selectExpr(s"(id * 15485867) % ${N*10} as k2", "id as k4") val df = df1.join(df2, col("k1") === col("k2") && col("k3") * 3 < col("k4"), "left_outer") assert(df.queryExecution.sparkPlan.find(_.isInstanceOf[SortMergeJoinExec]).isDefined) df.noop() } } ``` ``` Running benchmark: sort merge join with duplicates Running case: sort merge join with duplicates outer-smj-codegen off Stopped after 2 iterations, 2696 ms Running case: sort merge join with duplicates outer-smj-codegen on Stopped after 5 iterations, 6058 ms Java HotSpot(TM) 64-Bit Server VM 1.8.0_181-b13 on Mac OS X 10.16 Intel(R) Core(TM) i9-9980HK CPU @ 2.40GHz sort merge join with duplicates: Best Time(ms) Avg Time(ms) Stdev(ms) Rate(M/s) Per Row(ns) Relative ------------------------------------------------------------------------------------------------------------------------------------- sort merge join with duplicates outer-smj-codegen off 1333 1348 21 1.6 635.7 1.0X sort merge join with duplicates outer-smj-codegen on 1169 1212 47 1.8 557.4 1.1X ``` ### Does this PR introduce _any_ user-facing change? <!-- Note that it means *any* user-facing change including all aspects such as the documentation fix. If yes, please clarify the previous behavior and the change this PR proposes - provide the console output, description and/or an example to show the behavior difference if possible. If possible, please also clarify if this is a user-facing change compared to the released Spark versions or within the unreleased branches such as master. If no, write 'No'. --> No. ### How was this patch tested? <!-- If tests were added, say they were added here. Please make sure to add some test cases that check the changes thoroughly including negative and positive cases if possible. If it was tested in a way different from regular unit tests, please clarify how you tested step by step, ideally copy and paste-able, so that other reviewers can test and check, and descendants can verify in the future. If tests were not added, please describe why they were not added and/or why it was difficult to add. --> Added unit test in `WholeStageCodegenSuite.scala` and `WholeStageCodegenSuite.scala`. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: reviews-unsubscr...@spark.apache.org For additional commands, e-mail: reviews-h...@spark.apache.org