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GH-1382: Implement JDBC type discovery with GetXdbcTypeInfo #1391

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GH-1382: Implement JDBC type discovery with GetXdbcTypeInfo #1391

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024a13b
GH-1382: Implement JDBC type discovery with GetXdbcTypeInfo
hutiefang76 Oct 24, 2026
284386d
GH-1382: Preserve empty type info for unsupported servers
hutiefang76 Oct 26, 2026
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220 changes: 220 additions & 0 deletions ...light-sql-jdbc-core/src/main/java/org/apache/arrow/driver/jdbc/ArrowDatabaseMetadata.java
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Original file line number Diff line number Diff line change
Expand Up @@ -57,6 +57,8 @@
import org.apache.arrow.driver.jdbc.utils.SqlTypes;
import org.apache.arrow.driver.jdbc.utils.VectorSchemaRootTransformer;
import org.apache.arrow.flight.FlightInfo;
import org.apache.arrow.flight.FlightRuntimeException;
import org.apache.arrow.flight.FlightStatusCode;
import org.apache.arrow.flight.sql.FlightSqlColumnMetadata;
import org.apache.arrow.flight.sql.FlightSqlProducer.Schemas;
import org.apache.arrow.flight.sql.impl.FlightSql.SqlInfo;
Expand All @@ -72,10 +74,13 @@
import org.apache.arrow.flight.sql.impl.FlightSql.SupportedAnsi92SqlGrammarLevel;
import org.apache.arrow.flight.sql.impl.FlightSql.SupportedSqlGrammar;
import org.apache.arrow.memory.BufferAllocator;
import org.apache.arrow.vector.BitVector;
import org.apache.arrow.vector.IntVector;
import org.apache.arrow.vector.SmallIntVector;
import org.apache.arrow.vector.VarBinaryVector;
import org.apache.arrow.vector.VarCharVector;
import org.apache.arrow.vector.VectorSchemaRoot;
import org.apache.arrow.vector.complex.ListVector;
import org.apache.arrow.vector.extension.UuidType;
import org.apache.arrow.vector.ipc.ReadChannel;
import org.apache.arrow.vector.ipc.message.MessageSerializer;
Expand Down Expand Up @@ -147,6 +152,27 @@ public class ArrowDatabaseMetadata extends AvaticaDatabaseMetaData {
Field.nullable("SOURCE_DATA_TYPE", Types.MinorType.SMALLINT.getType()),
Field.notNullable("IS_AUTOINCREMENT", Types.MinorType.VARCHAR.getType()),
Field.notNullable("IS_GENERATEDCOLUMN", Types.MinorType.VARCHAR.getType())));
private static final Schema GET_TYPE_INFO_SCHEMA =
new Schema(
Arrays.asList(
Field.nullable("TYPE_NAME", Types.MinorType.VARCHAR.getType()),
Field.nullable("DATA_TYPE", Types.MinorType.INT.getType()),
Field.nullable("PRECISION", Types.MinorType.INT.getType()),
Field.nullable("LITERAL_PREFIX", Types.MinorType.VARCHAR.getType()),
Field.nullable("LITERAL_SUFFIX", Types.MinorType.VARCHAR.getType()),
Field.nullable("CREATE_PARAMS", Types.MinorType.VARCHAR.getType()),
Field.nullable("NULLABLE", Types.MinorType.SMALLINT.getType()),
Field.nullable("CASE_SENSITIVE", Types.MinorType.BIT.getType()),
Field.nullable("SEARCHABLE", Types.MinorType.SMALLINT.getType()),
Field.nullable("UNSIGNED_ATTRIBUTE", Types.MinorType.BIT.getType()),
Field.nullable("FIXED_PREC_SCALE", Types.MinorType.BIT.getType()),
Field.nullable("AUTO_INCREMENT", Types.MinorType.BIT.getType()),
Field.nullable("LOCAL_TYPE_NAME", Types.MinorType.VARCHAR.getType()),
Field.nullable("MINIMUM_SCALE", Types.MinorType.SMALLINT.getType()),
Field.nullable("MAXIMUM_SCALE", Types.MinorType.SMALLINT.getType()),
Field.nullable("SQL_DATA_TYPE", Types.MinorType.INT.getType()),
Field.nullable("SQL_DATETIME_SUB", Types.MinorType.INT.getType()),
Field.nullable("NUM_PREC_RADIX", Types.MinorType.INT.getType())));
private final AtomicBoolean isCachePopulated = new AtomicBoolean(false);
private final Map<SqlInfo, Object> cachedSqlInfo = new EnumMap<>(SqlInfo.class);
private static final Map<Integer, Integer> sqlTypesToFlightEnumConvertTypes = new HashMap<>();
Expand Down Expand Up @@ -1001,6 +1027,200 @@ public ResultSet getPrimaryKeys(final String catalog, final String schema, final
connection, flightInfoPrimaryKeys, transformer);
}

@Override
public ResultSet getTypeInfo() throws SQLException {
final ArrowFlightConnection connection = getConnection();
final BufferAllocator allocator = connection.getBufferAllocator();

final FlightInfo flightInfoTypeInfo;
try {
flightInfoTypeInfo = connection.getClientHandler().getXdbcTypeInfo();
} catch (final FlightRuntimeException e) {
if (e.status().code() == FlightStatusCode.UNIMPLEMENTED) {
// Compatible servers may not implement GetXdbcTypeInfo at all; keep the empty JDBC result.
return super.getTypeInfo();
}
throw new SQLException("Failed to retrieve type info.", e);
Comment on lines +1037 to +1043

@jbonofre jbonofre Oct 26, 2026

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This changes the behavior. getTypeInfo() used to return an empty 18-column result set without any RPC. Now any FlightRuntimeException becomes a SQLException, including UNIMPLEMENTED from servers that don't support CommandGetXdbcTypeInfo. BI tools and ORMs commonly call getTypeInfo() while setting up a connection, so those servers would now fail to connect.

Could we catch CallStatus.UNIMPLEMENTED here (and later), and return super.getTypeInfo() as before?
Only other failures should surface as SQLException.

Maybe we could add a test using setTypeInfoFlightInfoFailure(CallStatus.UNIMPLEMENTED..).

@hutiefang76 hutiefang76 Oct 26, 2026

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Implemented in 284386d: both getFlightInfo and stream initialization now fall back to super.getTypeInfo() for UNIMPLEMENTED. Other Flight failures still become SQLException.

Two real Flight-server regressions check the empty 18-column JDBC schema, no rows and allocator buffers returning to baseline. With identical final test bytes, the reviewed production revision failed those two cases; the fix passes all 11 focused tests. Local affected-reactor verification also passed: Flight SQL 97 tests; JDBC Core 1255 records, including 44 existing skips; packaged driver validation 2 integration tests. Upstream CI results for this follow-up remain pending.

AI-assisted patch and reply using DeepSeek and Codex; the tests above were executed locally.

}

try {
final ArrowFlightJdbcFlightStreamResultSet resultSet =
ArrowFlightJdbcFlightStreamResultSet.fromFlightInfo(
connection,
flightInfoTypeInfo,
(originalRoot, transformedRoot) -> {
if (transformedRoot == null) {
transformedRoot = VectorSchemaRoot.create(GET_TYPE_INFO_SCHEMA, allocator);
}
transformTypeInfoRoot(originalRoot, transformedRoot);
originalRoot.clear();
return transformedRoot;
});
// Empty streams do not initialize a cursor; retain the standard JDBC metadata columns.
if (resultSet.getMetaData().getColumnCount() == 0) {
resultSet.close();
return super.getTypeInfo();
}
return resultSet;
} catch (final FlightRuntimeException e) {
if (e.status().code() == FlightStatusCode.UNIMPLEMENTED) {
// The stream handshake may be the first call to reveal an unsupported GetXdbcTypeInfo.
return super.getTypeInfo();
}
throw new SQLException("Failed to retrieve type info.", e);
}
}

/**
* Maps a {@code CommandGetXdbcTypeInfo} root onto the 18 JDBC {@code getTypeInfo()} columns.
*
* <p>The rows are kept in the order the server sent them (including the server preference for
* types sharing a {@code DATA_TYPE}), the Flight {@code interval_precision} field is dropped as
* it has no JDBC counterpart, {@code create_params} is joined into a comma separated string, and
* {@code NULLABLE}, {@code SEARCHABLE}, {@code MINIMUM_SCALE} and {@code MAXIMUM_SCALE} are
* reported as nullable {@code SMALLINT} as required by the JDBC specification. No value is
* fabricated: SQL {@code NULL} stays {@code NULL}.
*
* @param originalRoot the root received from the server.
* @param transformedRoot the root the JDBC columns are written to; reused across batches.
*/
private static void transformTypeInfoRoot(
final VectorSchemaRoot originalRoot, final VectorSchemaRoot transformedRoot) {
final int rowCount = originalRoot.getRowCount();
if (rowCount == 0) {
transformedRoot.setRowCount(0);
return;
}

final VarCharVector typeName = (VarCharVector) transformedRoot.getVector("TYPE_NAME");
final IntVector dataType = (IntVector) transformedRoot.getVector("DATA_TYPE");
final IntVector precision = (IntVector) transformedRoot.getVector("PRECISION");
final VarCharVector literalPrefix = (VarCharVector) transformedRoot.getVector("LITERAL_PREFIX");
final VarCharVector literalSuffix = (VarCharVector) transformedRoot.getVector("LITERAL_SUFFIX");
final VarCharVector createParams = (VarCharVector) transformedRoot.getVector("CREATE_PARAMS");
final SmallIntVector nullable = (SmallIntVector) transformedRoot.getVector("NULLABLE");
final BitVector caseSensitive = (BitVector) transformedRoot.getVector("CASE_SENSITIVE");
final SmallIntVector searchable = (SmallIntVector) transformedRoot.getVector("SEARCHABLE");
final BitVector unsignedAttribute = (BitVector) transformedRoot.getVector("UNSIGNED_ATTRIBUTE");
final BitVector fixedPrecScale = (BitVector) transformedRoot.getVector("FIXED_PREC_SCALE");
final BitVector autoIncrement = (BitVector) transformedRoot.getVector("AUTO_INCREMENT");
final VarCharVector localTypeName =
(VarCharVector) transformedRoot.getVector("LOCAL_TYPE_NAME");
final SmallIntVector minimumScale = (SmallIntVector) transformedRoot.getVector("MINIMUM_SCALE");
final SmallIntVector maximumScale = (SmallIntVector) transformedRoot.getVector("MAXIMUM_SCALE");
final IntVector sqlDataType = (IntVector) transformedRoot.getVector("SQL_DATA_TYPE");
final IntVector sqlDatetimeSub = (IntVector) transformedRoot.getVector("SQL_DATETIME_SUB");
final IntVector numPrecRadix = (IntVector) transformedRoot.getVector("NUM_PREC_RADIX");

final VarCharVector serverTypeName = (VarCharVector) originalRoot.getVector("type_name");
final IntVector serverDataType = (IntVector) originalRoot.getVector("data_type");
final IntVector serverColumnSize = (IntVector) originalRoot.getVector("column_size");
final VarCharVector serverLiteralPrefix =
(VarCharVector) originalRoot.getVector("literal_prefix");
final VarCharVector serverLiteralSuffix =
(VarCharVector) originalRoot.getVector("literal_suffix");
final ListVector serverCreateParams = (ListVector) originalRoot.getVector("create_params");
final IntVector serverNullable = (IntVector) originalRoot.getVector("nullable");
final BitVector serverCaseSensitive = (BitVector) originalRoot.getVector("case_sensitive");
final IntVector serverSearchable = (IntVector) originalRoot.getVector("searchable");
final BitVector serverUnsignedAttribute =
(BitVector) originalRoot.getVector("unsigned_attribute");
final BitVector serverFixedPrecScale = (BitVector) originalRoot.getVector("fixed_prec_scale");
final BitVector serverAutoIncrement = (BitVector) originalRoot.getVector("auto_increment");
final VarCharVector serverLocalTypeName =
(VarCharVector) originalRoot.getVector("local_type_name");
final IntVector serverMinimumScale = (IntVector) originalRoot.getVector("minimum_scale");
final IntVector serverMaximumScale = (IntVector) originalRoot.getVector("maximum_scale");
final IntVector serverSqlDataType = (IntVector) originalRoot.getVector("sql_data_type");
final IntVector serverDatetimeSubcode = (IntVector) originalRoot.getVector("datetime_subcode");
final IntVector serverNumPrecRadix = (IntVector) originalRoot.getVector("num_prec_radix");

for (int i = 0; i < rowCount; i++) {
copyVarChar(serverTypeName, typeName, i);
copyInt(serverDataType, dataType, i);
copyInt(serverColumnSize, precision, i);
copyVarChar(serverLiteralPrefix, literalPrefix, i);
copyVarChar(serverLiteralSuffix, literalSuffix, i);
copyCreateParams(serverCreateParams, createParams, i);
copyIntAsSmallInt(serverNullable, nullable, i);
copyBit(serverCaseSensitive, caseSensitive, i);
copyIntAsSmallInt(serverSearchable, searchable, i);
copyBit(serverUnsignedAttribute, unsignedAttribute, i);
copyBit(serverFixedPrecScale, fixedPrecScale, i);
copyBit(serverAutoIncrement, autoIncrement, i);
copyVarChar(serverLocalTypeName, localTypeName, i);
copyIntAsSmallInt(serverMinimumScale, minimumScale, i);
copyIntAsSmallInt(serverMaximumScale, maximumScale, i);
copyInt(serverSqlDataType, sqlDataType, i);
copyInt(serverDatetimeSubcode, sqlDatetimeSub, i);
copyInt(serverNumPrecRadix, numPrecRadix, i);
}

transformedRoot.setRowCount(rowCount);
}

private static void copyInt(final IntVector source, final IntVector target, final int index) {
if (source.isNull(index)) {
target.setNull(index);
} else {
target.setSafe(index, source.get(index));
}
}

private static void copyIntAsSmallInt(
final IntVector source, final SmallIntVector target, final int index) {
if (source.isNull(index)) {
target.setNull(index);
} else {
target.setSafe(index, (short) source.get(index));
}
}

private static void copyBit(final BitVector source, final BitVector target, final int index) {
if (source.isNull(index)) {
target.setNull(index);
} else {
target.setSafe(index, source.get(index));
}
}

private static void copyVarChar(
final VarCharVector source, final VarCharVector target, final int index) {
if (source.isNull(index)) {
target.setNull(index);
} else {
target.setSafe(index, source.get(index));
}
}

/**
* Joins the {@code create_params} list into a comma separated string, preserving the difference
* between a SQL {@code NULL} list (reported as {@code NULL}) and an empty list (reported as an
* empty string).
*/
private static void copyCreateParams(
final ListVector source, final VarCharVector target, final int index) {
if (source.isNull(index)) {
target.setNull(index);
return;
}

final VarCharVector items = (VarCharVector) source.getDataVector();
final int start = source.getElementStartIndex(index);
final int end = source.getElementEndIndex(index);
final StringBuilder joined = new StringBuilder();
for (int i = start; i < end; i++) {
if (i > start) {
joined.append(',');
}
final Text item = items.getObject(i);
if (item != null) {
joined.append(item.toString());
}
}
target.setSafe(index, new Text(joined.toString()));
}

@Override
public ResultSet getColumns(
final String catalog,
Expand Down
9 changes: 9 additions & 0 deletions ...c-core/src/main/java/org/apache/arrow/driver/jdbc/client/ArrowFlightSqlClientHandler.java
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Original file line number Diff line number Diff line change
Expand Up @@ -605,6 +605,15 @@ public FlightInfo getSqlInfo(SqlInfo... info) {
return sqlClient.getSqlInfo(info, getOptions());
}

/**
* Makes an RPC "getXdbcTypeInfo" request based on the provided info.
*
* @return a {@code FlightInfo} of results.
*/
public FlightInfo getXdbcTypeInfo() {
return sqlClient.getXdbcTypeInfo(getOptions());
}

/**
* Makes an RPC "getPrimaryKeys" request based on the provided info.
*
Expand Down
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