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Support range predicate pushdown for string columns with collation in PostgreSQL connector #9746

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merged 1 commit into from
Dec 3, 2021
Merged

Support range predicate pushdown for string columns with collation in PostgreSQL connector #9746

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104 changes: 98 additions & 6 deletions plugin/trino-postgresql/src/main/java/io/trino/plugin/postgresql/PostgreSqlClient.java
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Original file line number Diff line number Diff line change
Expand Up @@ -165,6 +165,7 @@
import static io.trino.plugin.postgresql.PostgreSqlConfig.ArrayMapping.AS_JSON;
import static io.trino.plugin.postgresql.PostgreSqlConfig.ArrayMapping.DISABLED;
import static io.trino.plugin.postgresql.PostgreSqlSessionProperties.getArrayMapping;
import static io.trino.plugin.postgresql.PostgreSqlSessionProperties.isEnableStringPushdownWithCollate;
import static io.trino.plugin.postgresql.TypeUtils.arrayDepth;
import static io.trino.plugin.postgresql.TypeUtils.getArrayElementPgTypeName;
import static io.trino.plugin.postgresql.TypeUtils.getJdbcObjectArray;
Expand Down Expand Up @@ -234,7 +235,7 @@ public class PostgreSqlClient
private final List<String> tableTypes;
private final AggregateFunctionRewriter<JdbcExpression> aggregateFunctionRewriter;

private static final PredicatePushdownController POSTGRESQL_CHARACTER_PUSHDOWN = (session, domain) -> {
private static final PredicatePushdownController POSTGRESQL_STRING_PUSHDOWN_WITHOUT_COLLATE = (session, domain) -> {
checkArgument(
domain.getType() instanceof VarcharType || domain.getType() instanceof CharType,
"This PredicatePushdownController can be used only for chars and varchars");
Expand Down Expand Up @@ -506,13 +507,22 @@ public Optional<ColumnMapping> toColumnMapping(ConnectorSession session, Connect
}

case Types.CHAR:
if (isEnableStringPushdownWithCollate(session)) {
return Optional.of(charColumnMappingWithCollate(typeHandle.getRequiredColumnSize()));
}
return Optional.of(charColumnMapping(typeHandle.getRequiredColumnSize()));

case Types.VARCHAR:
if (!jdbcTypeName.equals("varchar")) {
// This can be e.g. an ENUM
if (isCollatable(jdbcTypeName) && isEnableStringPushdownWithCollate(session)) {
return Optional.of(typedVarcharColumnMappingWithCollate(jdbcTypeName));
}
return Optional.of(typedVarcharColumnMapping(jdbcTypeName));
}
if (isCollatable(jdbcTypeName) && isEnableStringPushdownWithCollate(session)) {
return Optional.of(varcharColumnMappingWithCollate(typeHandle.getRequiredColumnSize()));
}
return Optional.of(varcharColumnMapping(typeHandle.getRequiredColumnSize()));

case Types.BINARY:
Expand Down Expand Up @@ -749,14 +759,19 @@ private boolean isCollatable(JdbcColumnHandle column)
if (column.getColumnType() instanceof CharType || column.getColumnType() instanceof VarcharType) {
String jdbcTypeName = column.getJdbcTypeHandle().getJdbcTypeName()
.orElseThrow(() -> new TrinoException(JDBC_ERROR, "Type name is missing: " + column.getJdbcTypeHandle()));
// Only char (internally named bpchar)/varchar/text are the built-in collatable types
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return "bpchar".equals(jdbcTypeName) || "varchar".equals(jdbcTypeName) || "text".equals(jdbcTypeName);
return isCollatable(jdbcTypeName);
}

// non-textual types don't have the concept of collation
return false;
}

private boolean isCollatable(String jdbcTypeName)
{
// Only char (internally named bpchar)/varchar/text are the built-in collatable types
return "bpchar".equals(jdbcTypeName) || "varchar".equals(jdbcTypeName) || "text".equals(jdbcTypeName);
}

@Override
public boolean isTopNGuaranteed(ConnectorSession session)
{
Expand Down Expand Up @@ -833,7 +848,20 @@ private static ColumnMapping charColumnMapping(int charLength)
charType,
charReadFunction(charType),
charWriteFunction(),
POSTGRESQL_CHARACTER_PUSHDOWN);
POSTGRESQL_STRING_PUSHDOWN_WITHOUT_COLLATE);
}

private static ColumnMapping charColumnMappingWithCollate(int charLength)
{
if (charLength > CharType.MAX_LENGTH) {
return varcharColumnMappingWithCollate(charLength);
}
CharType charType = createCharType(charLength);
return ColumnMapping.sliceMapping(
charType,
charReadFunction(charType),
stringWriteFunctionWithCollate(),
FULL_PUSHDOWN);
}

private static ColumnMapping varcharColumnMapping(int varcharLength)
Expand All @@ -845,7 +873,38 @@ private static ColumnMapping varcharColumnMapping(int varcharLength)
varcharType,
varcharReadFunction(varcharType),
varcharWriteFunction(),
POSTGRESQL_CHARACTER_PUSHDOWN);
POSTGRESQL_STRING_PUSHDOWN_WITHOUT_COLLATE);
}

private static ColumnMapping varcharColumnMappingWithCollate(int varcharLength)
{
VarcharType varcharType = varcharLength <= VarcharType.MAX_LENGTH
? createVarcharType(varcharLength)
: createUnboundedVarcharType();
return ColumnMapping.sliceMapping(
varcharType,
varcharReadFunction(varcharType),
stringWriteFunctionWithCollate(),
FULL_PUSHDOWN);
}

private static SliceWriteFunction stringWriteFunctionWithCollate()
{
return new SliceWriteFunction()
{
@Override
public String getBindExpression()
{
return "? COLLATE \"C\"";
}

@Override
public void set(PreparedStatement statement, int index, Slice value)
throws SQLException
{
statement.setString(index, value.toStringUtf8());
}
};
}

private static ColumnMapping timeColumnMapping(int precision)
Expand Down Expand Up @@ -1161,12 +1220,45 @@ private static ColumnMapping typedVarcharColumnMapping(String jdbcTypeName)
return ColumnMapping.sliceMapping(
VARCHAR,
(resultSet, columnIndex) -> utf8Slice(resultSet.getString(columnIndex)),
typedVarcharWriteFunction(jdbcTypeName));
typedVarcharWriteFunction(jdbcTypeName),
POSTGRESQL_STRING_PUSHDOWN_WITHOUT_COLLATE);
}

private static ColumnMapping typedVarcharColumnMappingWithCollate(String jdbcTypeName)
{
return ColumnMapping.sliceMapping(
VARCHAR,
(resultSet, columnIndex) -> utf8Slice(resultSet.getString(columnIndex)),
typedVarcharWriteFunctionWithCollate(jdbcTypeName),
FULL_PUSHDOWN);
}

private static SliceWriteFunction typedVarcharWriteFunction(String jdbcTypeName)
{
String bindExpression = format("CAST(? AS %s)", requireNonNull(jdbcTypeName, "jdbcTypeName is null"));

return new SliceWriteFunction()
{
@Override
public String getBindExpression()
{
return bindExpression;
}

@Override
public void set(PreparedStatement statement, int index, Slice value)
throws SQLException
{
statement.setString(index, value.toStringUtf8());
}
};
}

private static SliceWriteFunction typedVarcharWriteFunctionWithCollate(String jdbcTypeName)
{
String collation = "COLLATE \"C\"";
String bindExpression = format("CAST(? AS %s) %s", requireNonNull(jdbcTypeName, "jdbcTypeName is null"), collation);

return new SliceWriteFunction()
{
@Override
Expand Down
13 changes: 13 additions & 0 deletions plugin/trino-postgresql/src/main/java/io/trino/plugin/postgresql/PostgreSqlConfig.java
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Expand Up @@ -22,6 +22,7 @@ public class PostgreSqlConfig
{
private ArrayMapping arrayMapping = ArrayMapping.DISABLED;
private boolean includeSystemTables;
private boolean enableStringPushdownWithCollate;

public enum ArrayMapping
{
Expand Down Expand Up @@ -55,4 +56,16 @@ public PostgreSqlConfig setIncludeSystemTables(boolean includeSystemTables)
this.includeSystemTables = includeSystemTables;
return this;
}

public boolean isEnableStringPushdownWithCollate()
{
return enableStringPushdownWithCollate;
}

@Config("postgresql.experimental.enable-string-pushdown-with-collate")
public PostgreSqlConfig setEnableStringPushdownWithCollate(boolean enableStringPushdownWithCollate)
{
this.enableStringPushdownWithCollate = enableStringPushdownWithCollate;
return this;
}
}
12 changes: 12 additions & 0 deletions ...rino-postgresql/src/main/java/io/trino/plugin/postgresql/PostgreSqlSessionProperties.java
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Expand Up @@ -23,12 +23,14 @@

import java.util.List;

import static io.trino.spi.session.PropertyMetadata.booleanProperty;
import static io.trino.spi.session.PropertyMetadata.enumProperty;

public final class PostgreSqlSessionProperties
implements SessionPropertiesProvider
{
public static final String ARRAY_MAPPING = "array_mapping";
public static final String ENABLE_STRING_PUSHDOWN_WITH_COLLATE = "enable_string_pushdown_with_collate";

private final List<PropertyMetadata<?>> sessionProperties;

Expand All @@ -41,6 +43,11 @@ public PostgreSqlSessionProperties(PostgreSqlConfig postgreSqlConfig)
"Handling of PostgreSql arrays",
ArrayMapping.class,
postgreSqlConfig.getArrayMapping(),
false),
booleanProperty(
ENABLE_STRING_PUSHDOWN_WITH_COLLATE,
"Enable string pushdown with collate (experimental)",
postgreSqlConfig.isEnableStringPushdownWithCollate(),
false));
}

Expand All @@ -54,4 +61,9 @@ public static ArrayMapping getArrayMapping(ConnectorSession session)
{
return session.getProperty(ARRAY_MAPPING, ArrayMapping.class);
}

public static boolean isEnableStringPushdownWithCollate(ConnectorSession session)
{
return session.getProperty(ENABLE_STRING_PUSHDOWN_WITH_COLLATE, Boolean.class);
}
}
1 change: 1 addition & 0 deletions plugin/trino-postgresql/src/test/java/io/trino/plugin/postgresql/PostgreSqlQueryRunner.java
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Expand Up @@ -58,6 +58,7 @@ public static DistributedQueryRunner createPostgreSqlQueryRunner(
connectorProperties.putIfAbsent("connection-password", server.getPassword());
connectorProperties.putIfAbsent("allow-drop-table", "true");
connectorProperties.putIfAbsent("postgresql.include-system-tables", "true");
//connectorProperties.putIfAbsent("postgresql.experimental.enable-string-pushdown-with-collate", "true");

queryRunner.installPlugin(new PostgreSqlPlugin());
queryRunner.createCatalog("postgresql", "postgresql", connectorProperties);
Expand Down
7 changes: 5 additions & 2 deletions plugin/trino-postgresql/src/test/java/io/trino/plugin/postgresql/TestPostgreSqlConfig.java
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Expand Up @@ -29,7 +29,8 @@ public void testDefaults()
{
assertRecordedDefaults(recordDefaults(PostgreSqlConfig.class)
.setArrayMapping(PostgreSqlConfig.ArrayMapping.DISABLED)
.setIncludeSystemTables(false));
.setIncludeSystemTables(false)
.setEnableStringPushdownWithCollate(false));
}

@Test
Expand All @@ -38,11 +39,13 @@ public void testExplicitPropertyMappings()
Map<String, String> properties = new ImmutableMap.Builder<String, String>()
.put("postgresql.array-mapping", "AS_ARRAY")
.put("postgresql.include-system-tables", "true")
.put("postgresql.experimental.enable-string-pushdown-with-collate", "true")
.build();

PostgreSqlConfig expected = new PostgreSqlConfig()
.setArrayMapping(PostgreSqlConfig.ArrayMapping.AS_ARRAY)
.setIncludeSystemTables(true);
.setIncludeSystemTables(true)
.setEnableStringPushdownWithCollate(true);

assertFullMapping(properties, expected);
}
Expand Down
61 changes: 61 additions & 0 deletions ...rino-postgresql/src/test/java/io/trino/plugin/postgresql/TestPostgreSqlConnectorTest.java
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Expand Up @@ -13,12 +13,16 @@
*/
package io.trino.plugin.postgresql;

import com.google.common.collect.ImmutableList;
import com.google.common.collect.ImmutableMap;
import io.airlift.units.Duration;
import io.trino.Session;
import io.trino.plugin.jdbc.BaseJdbcConnectorTest;
import io.trino.plugin.jdbc.JdbcColumnHandle;
import io.trino.plugin.jdbc.JdbcTableHandle;
import io.trino.plugin.jdbc.RemoteDatabaseEvent;
import io.trino.spi.connector.ColumnHandle;
import io.trino.spi.predicate.Range;
import io.trino.spi.predicate.TupleDomain;
import io.trino.sql.planner.plan.FilterNode;
import io.trino.sql.planner.plan.JoinNode;
Expand All @@ -42,7 +46,10 @@
import java.util.Map;
import java.util.UUID;

import static com.google.common.collect.MoreCollectors.onlyElement;
import static io.airlift.slice.Slices.utf8Slice;
import static io.trino.plugin.postgresql.PostgreSqlQueryRunner.createPostgreSqlQueryRunner;
import static io.trino.spi.type.VarcharType.createVarcharType;
import static io.trino.sql.planner.assertions.PlanMatchPattern.anyTree;
import static io.trino.sql.planner.assertions.PlanMatchPattern.node;
import static io.trino.sql.planner.assertions.PlanMatchPattern.tableScan;
Expand Down Expand Up @@ -82,6 +89,7 @@ protected boolean hasBehavior(TestingConnectorBehavior connectorBehavior)
{
switch (connectorBehavior) {
case SUPPORTS_PREDICATE_PUSHDOWN_WITH_VARCHAR_INEQUALITY:
case SUPPORTS_JOIN_PUSHDOWN_WITH_VARCHAR_INEQUALITY:
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return false;
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@takezoe takezoe Oct 25, 2021 •
edited
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Additional updates are necessary to support aggregation pushdown for varchar columns. Since I would focus on support range predicates pushdown in this pull request, I just introduced a new behavior that indicates whether aggregation pushdown is supported for varchar columns.

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Let's create a GitHub issue and add a TODO so that we can remove the additional behaviour once it's no longer needed (and other people know that this is something they can work on).

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Yeah, that makes sense (as long as this fix can be merged) and I would work on it once this pull request is completed. By the way, supporting type sensitive aggregation pushdown in JDBC plugins doesn't seem easy. Fundamental interface changes may be required.

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Yeah, I ran into some similar issues in #7320.

There were some ideas floated in #7320 (comment) (which we didn't end up doing since it looked like a one-off need at that time).

If you already have some direction in your mind it might be helpful to discuss it on #dev on Slack too (if you think the changes will be large and touch the SPI).

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Oh, will take a look at #7320 first. Thanks.


case SUPPORTS_TOPN_PUSHDOWN:
Expand Down Expand Up @@ -368,6 +376,59 @@ public void testPredicatePushdown()
anyTree(node(TableScanNode.class))));
}

@Test
public void testStringPushdownWithCollate()
{
Session session = Session.builder(getSession())
.setCatalogSessionProperty("postgresql", "enable_string_pushdown_with_collate", "true")
.build();

// varchar range
assertThat(query(session, "SELECT regionkey, nationkey, name FROM nation WHERE name BETWEEN 'POLAND' AND 'RPA'"))
.matches("VALUES (BIGINT '3', BIGINT '19', CAST('ROMANIA' AS varchar(25)))")
.isFullyPushedDown();

// varchar IN with small compaction threshold
assertThat(query(
Session.builder(session)
.setCatalogSessionProperty("postgresql", "domain_compaction_threshold", "1")
.build(),
"SELECT regionkey, nationkey, name FROM nation WHERE name IN ('POLAND', 'ROMANIA', 'VIETNAM')"))
.matches("VALUES " +
"(BIGINT '3', BIGINT '19', CAST('ROMANIA' AS varchar(25))), " +
"(BIGINT '2', BIGINT '21', CAST('VIETNAM' AS varchar(25)))")
// Verify that a FilterNode is retained and only a compacted domain is pushed down to connector as a range predicate
.isNotFullyPushedDown(node(FilterNode.class, tableScan(
tableHandle -> {
TupleDomain<ColumnHandle> constraint = ((JdbcTableHandle) tableHandle).getConstraint();
ColumnHandle nameColumn = constraint.getDomains().orElseThrow()
.keySet().stream()
.map(JdbcColumnHandle.class::cast)
.filter(column -> column.getColumnName().equals("name"))
.collect(onlyElement());
return constraint.getDomains().get().get(nameColumn).getValues().getRanges().getOrderedRanges()
.equals(ImmutableList.of(
Range.range(
createVarcharType(25),
utf8Slice("POLAND"), true,
utf8Slice("VIETNAM"), true)));
},
TupleDomain.all(),
ImmutableMap.of())));

// varchar predicate over join
Session joinPushdownEnabled = joinPushdownEnabled(session);
assertThat(query(joinPushdownEnabled, "SELECT c.name, n.name FROM customer c JOIN nation n ON c.custkey = n.nationkey WHERE address < 'TcGe5gaZNgVePxU5kRrvXBfkasDTea'"))
.isFullyPushedDown();
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// join on varchar columns is not pushed down
assertThat(query(joinPushdownEnabled, "SELECT c.name, n.name FROM customer c JOIN nation n ON c.address = n.name"))
.isNotFullyPushedDown(
node(JoinNode.class,
anyTree(node(TableScanNode.class)),
anyTree(node(TableScanNode.class))));
}

@Test
public void testDecimalPredicatePushdown()
throws Exception
Expand Down