io.druid.sql.calcite.schema.InformationSchema Maven / Gradle / Ivy
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* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
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* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
package io.druid.sql.calcite.schema;
import com.google.common.base.Function;
import com.google.common.base.Preconditions;
import com.google.common.base.Predicates;
import com.google.common.collect.FluentIterable;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.ImmutableMap;
import com.google.common.collect.Iterables;
import com.google.inject.Inject;
import io.druid.segment.column.ValueType;
import io.druid.sql.calcite.table.RowSignature;
import org.apache.calcite.DataContext;
import org.apache.calcite.jdbc.JavaTypeFactoryImpl;
import org.apache.calcite.linq4j.Enumerable;
import org.apache.calcite.linq4j.Linq4j;
import org.apache.calcite.rel.type.RelDataType;
import org.apache.calcite.rel.type.RelDataTypeFactory;
import org.apache.calcite.rel.type.RelDataTypeField;
import org.apache.calcite.rel.type.RelDataTypeSystem;
import org.apache.calcite.schema.ScannableTable;
import org.apache.calcite.schema.SchemaPlus;
import org.apache.calcite.schema.Statistic;
import org.apache.calcite.schema.Statistics;
import org.apache.calcite.schema.Table;
import org.apache.calcite.schema.TableMacro;
import org.apache.calcite.schema.impl.AbstractSchema;
import org.apache.calcite.sql.type.SqlTypeName;
import javax.annotation.Nullable;
import java.util.Collection;
import java.util.Map;
public class InformationSchema extends AbstractSchema
{
public static final String NAME = "INFORMATION_SCHEMA";
private static final String EMPTY_CATALOG = "";
private static final String SCHEMATA_TABLE = "SCHEMATA";
private static final String TABLES_TABLE = "TABLES";
private static final String COLUMNS_TABLE = "COLUMNS";
private static final RowSignature SCHEMATA_SIGNATURE = RowSignature
.builder()
.add("CATALOG_NAME", ValueType.STRING)
.add("SCHEMA_NAME", ValueType.STRING)
.add("SCHEMA_OWNER", ValueType.STRING)
.add("DEFAULT_CHARACTER_SET_CATALOG", ValueType.STRING)
.add("DEFAULT_CHARACTER_SET_SCHEMA", ValueType.STRING)
.add("DEFAULT_CHARACTER_SET_NAME", ValueType.STRING)
.add("SQL_PATH", ValueType.STRING)
.build();
private static final RowSignature TABLES_SIGNATURE = RowSignature
.builder()
.add("TABLE_CATALOG", ValueType.STRING)
.add("TABLE_SCHEMA", ValueType.STRING)
.add("TABLE_NAME", ValueType.STRING)
.add("TABLE_TYPE", ValueType.STRING)
.build();
private static final RowSignature COLUMNS_SIGNATURE = RowSignature
.builder()
.add("TABLE_CATALOG", ValueType.STRING)
.add("TABLE_SCHEMA", ValueType.STRING)
.add("TABLE_NAME", ValueType.STRING)
.add("COLUMN_NAME", ValueType.STRING)
.add("ORDINAL_POSITION", ValueType.STRING)
.add("COLUMN_DEFAULT", ValueType.STRING)
.add("IS_NULLABLE", ValueType.STRING)
.add("DATA_TYPE", ValueType.STRING)
.add("CHARACTER_MAXIMUM_LENGTH", ValueType.STRING)
.add("CHARACTER_OCTET_LENGTH", ValueType.STRING)
.add("NUMERIC_PRECISION", ValueType.STRING)
.add("NUMERIC_PRECISION_RADIX", ValueType.STRING)
.add("NUMERIC_SCALE", ValueType.STRING)
.add("DATETIME_PRECISION", ValueType.STRING)
.add("CHARACTER_SET_NAME", ValueType.STRING)
.add("COLLATION_NAME", ValueType.STRING)
.add("JDBC_TYPE", ValueType.LONG)
.build();
private static final RelDataTypeSystem TYPE_SYSTEM = RelDataTypeSystem.DEFAULT;
private final SchemaPlus rootSchema;
private final Map tableMap;
@Inject
public InformationSchema(final SchemaPlus rootSchema)
{
this.rootSchema = Preconditions.checkNotNull(rootSchema, "rootSchema");
this.tableMap = ImmutableMap.of(
SCHEMATA_TABLE, new SchemataTable(),
TABLES_TABLE, new TablesTable(),
COLUMNS_TABLE, new ColumnsTable()
);
}
@Override
protected Map getTableMap()
{
return tableMap;
}
class SchemataTable implements ScannableTable
{
@Override
public Enumerable scan(final DataContext root)
{
final FluentIterable results = FluentIterable
.from(rootSchema.getSubSchemaNames())
.transform(
new Function()
{
@Override
public Object[] apply(final String schemaName)
{
final SchemaPlus subSchema = rootSchema.getSubSchema(schemaName);
return new Object[]{
EMPTY_CATALOG, // CATALOG_NAME
subSchema.getName(), // SCHEMA_NAME
null, // SCHEMA_OWNER
null, // DEFAULT_CHARACTER_SET_CATALOG
null, // DEFAULT_CHARACTER_SET_SCHEMA
null, // DEFAULT_CHARACTER_SET_NAME
null // SQL_PATH
};
}
}
);
return Linq4j.asEnumerable(results);
}
@Override
public RelDataType getRowType(final RelDataTypeFactory typeFactory)
{
return SCHEMATA_SIGNATURE.getRelDataType(typeFactory);
}
@Override
public Statistic getStatistic()
{
return Statistics.UNKNOWN;
}
@Override
public TableType getJdbcTableType()
{
return TableType.SYSTEM_TABLE;
}
}
class TablesTable implements ScannableTable
{
@Override
public Enumerable scan(final DataContext root)
{
final FluentIterable results = FluentIterable
.from(rootSchema.getSubSchemaNames())
.transformAndConcat(
new Function>()
{
@Override
public Iterable apply(final String schemaName)
{
final SchemaPlus subSchema = rootSchema.getSubSchema(schemaName);
return Iterables.filter(
Iterables.concat(
FluentIterable.from(subSchema.getTableNames()).transform(
new Function()
{
@Override
public Object[] apply(final String tableName)
{
return new Object[]{
EMPTY_CATALOG, // TABLE_CATALOG
schemaName, // TABLE_SCHEMA
tableName, // TABLE_NAME
subSchema.getTable(tableName).getJdbcTableType().toString() // TABLE_TYPE
};
}
}
),
FluentIterable.from(subSchema.getFunctionNames()).transform(
new Function()
{
@Override
public Object[] apply(final String functionName)
{
if (getView(subSchema, functionName) != null) {
return new Object[]{
EMPTY_CATALOG, // TABLE_CATALOG
schemaName, // TABLE_SCHEMA
functionName, // TABLE_NAME
"VIEW" // TABLE_TYPE
};
} else {
return null;
}
}
}
)
),
Predicates.notNull()
);
}
}
);
return Linq4j.asEnumerable(results);
}
@Override
public RelDataType getRowType(final RelDataTypeFactory typeFactory)
{
return TABLES_SIGNATURE.getRelDataType(typeFactory);
}
@Override
public Statistic getStatistic()
{
return Statistics.UNKNOWN;
}
@Override
public TableType getJdbcTableType()
{
return TableType.SYSTEM_TABLE;
}
}
class ColumnsTable implements ScannableTable
{
@Override
public Enumerable scan(final DataContext root)
{
final FluentIterable results = FluentIterable
.from(rootSchema.getSubSchemaNames())
.transformAndConcat(
new Function>()
{
@Override
public Iterable apply(final String schemaName)
{
final SchemaPlus subSchema = rootSchema.getSubSchema(schemaName);
final JavaTypeFactoryImpl typeFactory = new JavaTypeFactoryImpl(TYPE_SYSTEM);
return Iterables.concat(
Iterables.filter(
Iterables.concat(
FluentIterable.from(subSchema.getTableNames()).transform(
new Function>()
{
@Override
public Iterable apply(final String tableName)
{
return generateColumnMetadata(
schemaName,
tableName,
subSchema.getTable(tableName),
typeFactory
);
}
}
),
FluentIterable.from(subSchema.getFunctionNames()).transform(
new Function>()
{
@Override
public Iterable apply(final String functionName)
{
final TableMacro viewMacro = getView(subSchema, functionName);
if (viewMacro == null) {
return null;
}
return generateColumnMetadata(
schemaName,
functionName,
viewMacro.apply(ImmutableList.of()),
typeFactory
);
}
}
)
),
Predicates.notNull()
)
);
}
}
);
return Linq4j.asEnumerable(results);
}
@Override
public RelDataType getRowType(final RelDataTypeFactory typeFactory)
{
return COLUMNS_SIGNATURE.getRelDataType(typeFactory);
}
@Override
public Statistic getStatistic()
{
return Statistics.UNKNOWN;
}
@Override
public TableType getJdbcTableType()
{
return TableType.SYSTEM_TABLE;
}
@Nullable
private Iterable generateColumnMetadata(
final String schemaName,
final String tableName,
final Table table,
final RelDataTypeFactory typeFactory
)
{
if (table == null) {
return null;
}
return FluentIterable
.from(table.getRowType(typeFactory).getFieldList())
.transform(
new Function()
{
@Override
public Object[] apply(final RelDataTypeField field)
{
final RelDataType type = field.getType();
boolean isNumeric = SqlTypeName.NUMERIC_TYPES.contains(type.getSqlTypeName());
boolean isCharacter = SqlTypeName.CHAR_TYPES.contains(type.getSqlTypeName());
boolean isDateTime = SqlTypeName.DATETIME_TYPES.contains(type.getSqlTypeName());
return new Object[]{
EMPTY_CATALOG, // TABLE_CATALOG
schemaName, // TABLE_SCHEMA
tableName, // TABLE_NAME
field.getName(), // COLUMN_NAME
String.valueOf(field.getIndex()), // ORDINAL_POSITION
"", // COLUMN_DEFAULT
type.isNullable() ? "YES" : "NO", // IS_NULLABLE
type.getSqlTypeName().toString(), // DATA_TYPE
null, // CHARACTER_MAXIMUM_LENGTH
null, // CHARACTER_OCTET_LENGTH
isNumeric ? String.valueOf(type.getPrecision()) : null, // NUMERIC_PRECISION
isNumeric ? "10" : null, // NUMERIC_PRECISION_RADIX
isNumeric ? String.valueOf(type.getScale()) : null, // NUMERIC_SCALE
isDateTime ? String.valueOf(type.getPrecision()) : null, // DATETIME_PRECISION
isCharacter ? type.getCharset().name() : null, // CHARACTER_SET_NAME
isCharacter ? type.getCollation().getCollationName() : null, // COLLATION_NAME
type.getSqlTypeName().getJdbcOrdinal() // JDBC_TYPE (Druid extension)
};
}
}
);
}
}
/**
* Return a view macro that may or may not be defined in a certain schema. If it's not defined, returns null.
*
* @param schemaPlus schema
* @param functionName function name
*
* @return view, or null
*/
@Nullable
private static TableMacro getView(final SchemaPlus schemaPlus, final String functionName)
{
// Look for a zero-arg function that is also a TableMacro. The returned value
// is never null so we don't need to check for that.
final Collection functions =
schemaPlus.getFunctions(functionName);
for (org.apache.calcite.schema.Function function : functions) {
if (function.getParameters().isEmpty() && function instanceof TableMacro) {
return (TableMacro) function;
}
}
return null;
}
}
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