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Posted to commits@hudi.apache.org by GitBox <gi...@apache.org> on 2021/11/23 02:18:59 UTC
[GitHub] [hudi] xiarixiaoyao commented on a change in pull request #4060: [HUDI-2814][WIP] Addressing issues w/ Z-order Layout Optimization
xiarixiaoyao commented on a change in pull request #4060:
URL: https://github.com/apache/hudi/pull/4060#discussion_r754763584
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File path: hudi-spark-datasource/hudi-spark/src/main/scala/org/apache/spark/sql/hudi/DataSkippingUtils.scala
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@@ -29,148 +30,186 @@ import org.apache.spark.sql.functions.col
import org.apache.spark.sql.sources.Filter
import org.apache.spark.sql.types.{StringType, StructType}
import org.apache.spark.sql.vectorized.ColumnarBatch
+import org.apache.spark.sql.{AnalysisException, SparkSession}
import org.apache.spark.unsafe.types.UTF8String
import scala.collection.JavaConverters._
-object DataSkippingUtils {
+object DataSkippingUtils extends Logging {
/**
- * create z_index filter and push those filters to index table to filter all candidate scan files.
- * @param condition origin filter from query.
- * @param indexSchema schema from index table.
- * @return filters for index table.
- */
- def createZindexFilter(condition: Expression, indexSchema: StructType): Expression = {
- def buildExpressionInternal(colName: Seq[String], statisticValue: String): Expression = {
- val appendColName = UnresolvedAttribute(colName).name + statisticValue
- col(appendColName).expr
- }
-
- def reWriteCondition(colName: Seq[String], conditionExpress: Expression): Expression = {
- val appendColName = UnresolvedAttribute(colName).name + "_minValue"
- if (indexSchema.exists(p => p.name == appendColName)) {
- conditionExpress
- } else {
- Literal.TrueLiteral
- }
- }
-
- val minValue = (colName: Seq[String]) => buildExpressionInternal(colName, "_minValue")
- val maxValue = (colName: Seq[String]) => buildExpressionInternal(colName, "_maxValue")
- val num_nulls = (colName: Seq[String]) => buildExpressionInternal(colName, "_num_nulls")
-
- condition match {
- // query filter "colA = b" convert it to "colA_minValue <= b and colA_maxValue >= b" for index table
+ * Translates provided {@link filterExpr} into corresponding filter-expression for Z-index index table
+ * to filter out candidate files that would hold records matching the original filter
+ *
+ * @param filterExpr original filter from query
+ * @param indexSchema index table schema
+ * @return filter for Z-index table
+ */
+ def createZIndexLookupFilter(filterExpr: Expression, indexSchema: StructType): Expression = {
+
+ def minValue(colName: String) = col(getMinColumnNameFor(colName)).expr
+ def maxValue(colName: String) = col(getMaxColumnNameFor(colName)).expr
+ def numNulls(colName: String) = col(getNumNullsColumnNameFor(colName)).expr
+
+ def colContainsValuesEqualToLiteral(colName: String, value: Literal) =
+ // Only case when column C contains value V is when min(C) <= V <= max(c)
+ And(LessThanOrEqual(minValue(colName), value), GreaterThanOrEqual(maxValue(colName), value))
+
+ def colContainsValuesEqualToLiterals(colName: String, list: Seq[Literal]) =
+ // Only case when column C contains _any_ of the values V1, V2, etc is when either
+ // min(C) <= V1 <= max(c) OR
+ // min(C) <= V2 <= max(c) OR
+ // ...
+ list.map { lit => colContainsValuesEqualToLiteral(colName, lit) }.reduce(Or)
+
+ filterExpr match {
+ // Filter "colA = b"
+ // Translates to "colA_minValue <= b AND colA_maxValue >= b" condition for index lookup
case EqualTo(attribute: AttributeReference, value: Literal) =>
- val colName = getTargetColNameParts(attribute)
- reWriteCondition(colName, And(LessThanOrEqual(minValue(colName), value), GreaterThanOrEqual(maxValue(colName), value)))
- // query filter "b = colA" convert it to "colA_minValue <= b and colA_maxValue >= b" for index table
+ val colName = getTargetColName(attribute, indexSchema)
+ colContainsValuesEqualToLiteral(colName, value)
+ // Filter "b = colA"
+ // Translates to "colA_minValue <= b AND colA_maxValue >= b" condition for index lookup
case EqualTo(value: Literal, attribute: AttributeReference) =>
- val colName = getTargetColNameParts(attribute)
- reWriteCondition(colName, And(LessThanOrEqual(minValue(colName), value), GreaterThanOrEqual(maxValue(colName), value)))
- // query filter "colA = null" convert it to "colA_num_nulls = null" for index table
+ val colName = getTargetColName(attribute, indexSchema)
+ colContainsValuesEqualToLiteral(colName, value)
+ // Filter "colA = null"
+ // Translates to "colA_num_nulls = null" for index lookup
case equalNullSafe @ EqualNullSafe(_: AttributeReference, _ @ Literal(null, _)) =>
- val colName = getTargetColNameParts(equalNullSafe.left)
- reWriteCondition(colName, EqualTo(num_nulls(colName), equalNullSafe.right))
- // query filter "colA < b" convert it to "colA_minValue < b" for index table
+ val colName = getTargetColName(equalNullSafe.left, indexSchema)
+ EqualTo(numNulls(colName), equalNullSafe.right)
+ // Filter "colA < b"
+ // Translates to "colA_minValue < b" for index lookup
case LessThan(attribute: AttributeReference, value: Literal) =>
- val colName = getTargetColNameParts(attribute)
- reWriteCondition(colName,LessThan(minValue(colName), value))
- // query filter "b < colA" convert it to "colA_maxValue > b" for index table
+ val colName = getTargetColName(attribute, indexSchema)
+ LessThan(minValue(colName), value)
+ // Filter "b < colA"
+ // Translates to "b < colA_maxValue" for index lookup
case LessThan(value: Literal, attribute: AttributeReference) =>
- val colName = getTargetColNameParts(attribute)
- reWriteCondition(colName, GreaterThan(maxValue(colName), value))
- // query filter "colA > b" convert it to "colA_maxValue > b" for index table
+ val colName = getTargetColName(attribute, indexSchema)
+ GreaterThan(maxValue(colName), value)
+ // Filter "colA > b"
+ // Translates to "colA_maxValue > b" for index lookup
case GreaterThan(attribute: AttributeReference, value: Literal) =>
- val colName = getTargetColNameParts(attribute)
- reWriteCondition(colName, GreaterThan(maxValue(colName), value))
- // query filter "b > colA" convert it to "colA_minValue < b" for index table
+ val colName = getTargetColName(attribute, indexSchema)
+ GreaterThan(maxValue(colName), value)
+ // Filter "b > colA"
+ // Translates to "b > colA_minValue" for index lookup
case GreaterThan(value: Literal, attribute: AttributeReference) =>
- val colName = getTargetColNameParts(attribute)
- reWriteCondition(colName, LessThan(minValue(colName), value))
- // query filter "colA <= b" convert it to "colA_minValue <= b" for index table
+ val colName = getTargetColName(attribute, indexSchema)
+ LessThan(minValue(colName), value)
+ // Filter "colA <= b"
+ // Translates to "colA_minValue <= b" for index lookup
case LessThanOrEqual(attribute: AttributeReference, value: Literal) =>
- val colName = getTargetColNameParts(attribute)
- reWriteCondition(colName, LessThanOrEqual(minValue(colName), value))
- // query filter "b <= colA" convert it to "colA_maxValue >= b" for index table
+ val colName = getTargetColName(attribute, indexSchema)
+ LessThanOrEqual(minValue(colName), value)
+ // Filter "b <= colA"
+ // Translates to "b <= colA_maxValue" for index lookup
case LessThanOrEqual(value: Literal, attribute: AttributeReference) =>
- val colName = getTargetColNameParts(attribute)
- reWriteCondition(colName, GreaterThanOrEqual(maxValue(colName), value))
- // query filter "colA >= b" convert it to "colA_maxValue >= b" for index table
+ val colName = getTargetColName(attribute, indexSchema)
+ GreaterThanOrEqual(maxValue(colName), value)
+ // Filter "colA >= b"
+ // Translates to "colA_maxValue >= b" for index lookup
case GreaterThanOrEqual(attribute: AttributeReference, right: Literal) =>
- val colName = getTargetColNameParts(attribute)
+ val colName = getTargetColName(attribute, indexSchema)
GreaterThanOrEqual(maxValue(colName), right)
- // query filter "b >= colA" convert it to "colA_minValue <= b" for index table
+ // Filter "b >= colA"
+ // Translates to "b >= colA_minValue" for index lookup
case GreaterThanOrEqual(value: Literal, attribute: AttributeReference) =>
- val colName = getTargetColNameParts(attribute)
- reWriteCondition(colName, LessThanOrEqual(minValue(colName), value))
- // query filter "colA is null" convert it to "colA_num_nulls > 0" for index table
+ val colName = getTargetColName(attribute, indexSchema)
+ LessThanOrEqual(minValue(colName), value)
+ // Filter "colA is null"
+ // Translates to "colA_num_nulls > 0" for index lookup
case IsNull(attribute: AttributeReference) =>
- val colName = getTargetColNameParts(attribute)
- reWriteCondition(colName, GreaterThan(num_nulls(colName), Literal(0)))
- // query filter "colA is not null" convert it to "colA_num_nulls = 0" for index table
+ val colName = getTargetColName(attribute, indexSchema)
+ GreaterThan(numNulls(colName), Literal(0))
+ // Filter "colA is not null"
+ // Translates to "colA_num_nulls = 0" for index lookup
case IsNotNull(attribute: AttributeReference) =>
- val colName = getTargetColNameParts(attribute)
- reWriteCondition(colName, EqualTo(num_nulls(colName), Literal(0)))
- // query filter "colA in (a,b)" convert it to " (colA_minValue <= a and colA_maxValue >= a) or (colA_minValue <= b and colA_maxValue >= b) " for index table
+ val colName = getTargetColName(attribute, indexSchema)
+ EqualTo(numNulls(colName), Literal(0))
+ // Filter "colA in (a, b, ...)"
+ // Translates to "(colA_minValue <= a AND colA_maxValue >= a) OR (colA_minValue <= b AND colA_maxValue >= b)" for index lookup
case In(attribute: AttributeReference, list: Seq[Literal]) =>
- val colName = getTargetColNameParts(attribute)
- reWriteCondition(colName, list.map { lit =>
- And(LessThanOrEqual(minValue(colName), lit), GreaterThanOrEqual(maxValue(colName), lit))
- }.reduce(Or))
- // query filter "colA like xxx" convert it to " (colA_minValue <= xxx and colA_maxValue >= xxx) or (colA_min start with xxx or colA_max start with xxx) " for index table
+ val colName = getTargetColName(attribute, indexSchema)
+ colContainsValuesEqualToLiterals(colName, list)
+ // Filter "colA like xxx"
+ // Translates to "colA_minValue <= xxx AND colA_maxValue >= xxx" for index lookup
+ // NOTE: That this operator only matches string prefixes, and this is
+ // essentially equivalent to "colA = b" expression
case StartsWith(attribute, v @ Literal(_: UTF8String, _)) =>
- val colName = getTargetColNameParts(attribute)
- reWriteCondition(colName, Or(And(LessThanOrEqual(minValue(colName), v), GreaterThanOrEqual(maxValue(colName), v)) ,
- Or(StartsWith(minValue(colName), v), StartsWith(maxValue(colName), v))))
- // query filter "colA not in (a, b)" convert it to " (not( colA_minValue = a and colA_maxValue = a)) and (not( colA_minValue = b and colA_maxValue = b)) " for index table
+ val colName = getTargetColName(attribute, indexSchema)
+ colContainsValuesEqualToLiteral(colName, v)
+ // Filter "colA not in (a, b, ...)"
+ // Translates to "(colA_minValue > a OR colA_maxValue < a) AND (colA_minValue > b OR colA_maxValue < b)" for index lookup
+ // NOTE: This is an inversion of `in (a, b, ...)` expr
case Not(In(attribute: AttributeReference, list: Seq[Literal])) =>
- val colName = getTargetColNameParts(attribute)
- reWriteCondition(colName, list.map { lit =>
- Not(And(EqualTo(minValue(colName), lit), EqualTo(maxValue(colName), lit)))
- }.reduce(And))
- // query filter "colA != b" convert it to "not ( colA_minValue = b and colA_maxValue = b )" for index table
+ val colName = getTargetColName(attribute, indexSchema)
+ Not(colContainsValuesEqualToLiterals(colName, list))
+ // Filter "colA != b"
+ // Translates to "colA_minValue > b OR colA_maxValue < b" (which is an inversion of expr for "colA = b") for index lookup
+ // NOTE: This is an inversion of `colA = b` expr
case Not(EqualTo(attribute: AttributeReference, value: Literal)) =>
- val colName = getTargetColNameParts(attribute)
- reWriteCondition(colName, Not(And(EqualTo(minValue(colName), value), EqualTo(maxValue(colName), value))))
- // query filter "b != colA" convert it to "not ( colA_minValue = b and colA_maxValue = b )" for index table
+ val colName = getTargetColName(attribute, indexSchema)
+ Not(colContainsValuesEqualToLiteral(colName, value))
+ // Filter "b != colA"
+ // Translates to "colA_minValue > b OR colA_maxValue < b" (which is an inversion of expr for "colA = b") for index lookup
+ // NOTE: This is an inversion of `colA != b` expr
case Not(EqualTo(value: Literal, attribute: AttributeReference)) =>
- val colName = getTargetColNameParts(attribute)
- reWriteCondition(colName, Not(And(EqualTo(minValue(colName), value), EqualTo(maxValue(colName), value))))
- // query filter "colA not like xxxx" convert it to "not ( colA_minValue startWith xxx and colA_maxValue startWith xxx)" for index table
+ val colName = getTargetColName(attribute, indexSchema)
+ Not(colContainsValuesEqualToLiteral(colName, value))
+ // Filter "colA not like xxx"
+ // Translates to "!(colA_minValue <= xxx AND colA_maxValue >= xxx)" for index lookup
+ // NOTE: This is a inversion of "colA like xxx" assuming that colA is a string-based type
case Not(StartsWith(attribute, value @ Literal(_: UTF8String, _))) =>
- val colName = getTargetColNameParts(attribute)
- reWriteCondition(colName, Not(And(StartsWith(minValue(colName), value), StartsWith(maxValue(colName), value))))
+ val colName = getTargetColName(attribute, indexSchema)
+ Not(colContainsValuesEqualToLiteral(colName, value))
+
case or: Or =>
- val resLeft = createZindexFilter(or.left, indexSchema)
- val resRight = createZindexFilter(or.right, indexSchema)
+ val resLeft = createZIndexLookupFilter(or.left, indexSchema)
+ val resRight = createZIndexLookupFilter(or.right, indexSchema)
Or(resLeft, resRight)
case and: And =>
- val resLeft = createZindexFilter(and.left, indexSchema)
- val resRight = createZindexFilter(and.right, indexSchema)
+ val resLeft = createZIndexLookupFilter(and.left, indexSchema)
+ val resRight = createZIndexLookupFilter(and.right, indexSchema)
And(resLeft, resRight)
case expr: Expression =>
Literal.TrueLiteral
}
}
- /**
- * Extracts name from a resolved expression referring to a nested or non-nested column.
- */
- def getTargetColNameParts(resolvedTargetCol: Expression): Seq[String] = {
+ private def checkColIsIndexed(colName: String, indexSchema: StructType): Boolean = {
+ Set.apply(
+ getMinColumnNameFor(colName),
+ getMaxColumnNameFor(colName),
+ getNumNullsColumnNameFor(colName)
+ )
+ .forall(stat => indexSchema.exists(_.name == stat))
+ }
+
+ private def getTargetColName(resolvedExpr: Expression, indexSchema: StructType): String = {
+ val colName = UnresolvedAttribute(getTargetColNameParts(resolvedExpr)).name
+
+ // Verify that the column is indexed
+ // NOTE: That in case filtering expression contains referenced to a column that is NOT
+ // indexed data pruning becomes (largely) impossible
+ if (!checkColIsIndexed(colName, indexSchema)) {
+ logDebug(s"Filtering expression contains column that is not indexed ($colName)")
+ throw new AnalysisException(s"Filtering expression contains column that is not indexed ($colName)")
Review comment:
Sorry, I may not agree with you here. select * from T where A= or B = C= , those fitler will be rewrite to A = xx or b= xx or literal.trueliteral. Due to the existence of this literal.trueliteral we can push those fitler to index table directly, This will not cause any problems。
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