[jdbc-v2] `DataLakeCatalog` is not present in `getSchemas()` result or avoid using `system.*` where possible.

Start at the JDBC DatabaseMetaData getSchemas() and getTables() entry points and reproduce the issue against a database using the DataLakeCatalog engine. Compare the current system.databases lookup with SHOW DATABASES and verify metadata calls involving DataLakeCatalog do not produce the documented access error; the issue is done when the intended option or behavior is covered by tests.

Description

Databases with engine DataLakeCatalog are not visible when requested via DataBaseMetadata because driver uses system.databases to fetch this information.

Workaround: show_data_lake_catalogs_in_system_tables=1 settings in session or profile.

Note

As SHOW DATABASES return better information - JDBC Driver should make it at least an option.

DBeaver and Metabase

When workaround applied these products getting exception trying to read tables information.
See https://clickhouse.com/docs/operations/settings/settings#database_datalake_require_metadata_access

2026-07-02T21:19:42+02:00 ERROR metabase.sync.fetch-metadata Error while fetching metadata with 'db-metadata',java.sql.SQLException: Code: 736. DB::Exception: Received error 736 while fetching table metadata for existing table 'product_analyst_team.vw_ap_integrations_2026'. If you want this error to be ignored, use database_datalake_require_metadata_access=0. Error: Code: 736. DB::Exception: Cannot read table `sandbox.product_analyst_team.vw_ap_integrations_2026` because it doesn't have storage location. It means that it's not a DeltaLake table, and it's unreadable with Unity catalog in ClickHouse. (...,	at com.clickhouse.jdbc.internal.ExceptionUtils.toSqlState(ExceptionUtils.java:68),	at com.clickhouse.jdbc.internal.ExceptionUtils.toSqlState(ExceptionUtils.java:43),	at com.clickhouse.jdbc.StatementImpl.executeQueryImpl(StatementImpl.java:196),	at com.clickhouse.jdbc.PreparedStatementImpl.executeQuery(PreparedStatementImpl.java:138),	at com.clickhouse.jdbc.metadata.DatabaseMetaDataImpl.getTables(DatabaseMetaDataImpl.java:998),	at com.mchange.v2.c3p0.impl.NewProxyDatabaseMetaData.getTables(NewProxyDatabaseMetaData.java:4174),	at metabase.driver.clickhouse_introspection$get_tables_from_metadata.invokeStatic(clickhouse_introspection.clj:109),	at metabase.driver.clickhouse_introspection$get_tables_from_metadata.invoke(clickhouse_introspection.clj:107),	at metabase.driver.clickhouse_introspection$get_all_tables_in_all_dbs$fn__173063.invoke(clickhouse_introspection.clj:128),	at metabase.driver.clickhouse$fn__173529$fn__173531.invoke(clickhouse.clj:102),	at metabase.driver.sql_jdbc.execute$do_with_resolved_connection.invokeStatic(execute.clj:366),	at metabase.driver.sql_jdbc.execute$do_with_resolved_connection.invoke(execute.clj:338),	at metabase.driver.clickhouse$fn__173529.invokeStatic(clickhouse.clj:79),	at metabase.driver.clickhouse$fn__173529.invoke(clickhouse.clj:77),	at clojure.lang.MultiFn.invoke(MultiFn.java:244),	at metabase.driver.clickhouse_introspection$get_all_tables_in_all_dbs.invokeStatic(clickhouse_introspection.clj:125),	at metabase.driver.clickhouse_introspection$get_all_tables_in_all_dbs.invoke(clickhouse_introspection.clj:119),	at metabase.driver.clickhouse_introspection$fn__173076.invokeStatic(clickhouse_introspection.clj:170),	at metabase.driver.clickhouse_introspection$fn__173076.invoke(clickhouse_introspection.clj:166)
2026-07-02T21:19:42+02:00 WARN metabase.sync.util Error in sync step Sync metadata for clickhouse Database 43 ''test-clickhouse-cloud'',java.sql.SQLException: Code: 736. DB::Exception: Received error 736 while fetching table metadata for existing table 'product_analyst_team.vw_ap_integrations_2026'. If you want this error to be ignored, use database_datalake_require_metadata_access=0. Error: Code: 736. DB::Exception: Cannot read table `sandbox.product_analyst_team.vw_ap_integrations_2026` because it doesn't have storage location. It means that it's not a DeltaLake table, and it's unreadable with Unity catalog in ClickHouse. (...,	at com.clickhouse.jdbc.internal.ExceptionUtils.toSqlState(ExceptionUtils.java:68),	at com.clickhouse.jdbc.internal.ExceptionUtils.toSqlState(ExceptionUtils.java:43),	at com.clickhouse.jdbc.StatementImpl.executeQueryImpl(StatementImpl.java:196),	at com.clickhouse.jdbc.PreparedStatementImpl.executeQuery(PreparedStatementImpl.java:138),	at com.clickhouse.jdbc.metadata.DatabaseMetaDataImpl.getTables(DatabaseMetaDataImpl.java:998),	at com.mchange.v2.c3p0.impl.NewProxyDatabaseMetaData.getTables(NewProxyDatabaseMetaData.java:4174),	at metabase.driver.clickhouse_introspection$get_tables_from_metadata.invokeStatic(clickhouse_introspection.clj:109),	at metabase.driver.clickhouse_introspection$get_tables_from_metadata.invoke(clickhouse_introspection.clj:107),	at metabase.driver.clickhouse_introspection$get_all_tables_in_all_dbs$fn__173063.invoke(clickhouse_introspection.clj:128),	at metabase.driver.clickhouse$fn__173529$fn__173531.invoke(clickhouse.clj:102),	at metabase.driver.sql_jdbc.execute$do_with_resolved_connection.invokeStatic(execute.clj:366),	at metabase.driver.sql_jdbc.execute$do_with_resolved_connection.invoke(execute.clj:338),	at metabase.driver.clickhouse$fn__173529.invokeStatic(clickhouse.clj:79),	at metabase.driver.clickhouse$fn__173529.invoke(clickhouse.clj:77),	at clojure.lang.MultiFn.invoke(MultiFn.java:244),	at metabase.driver.clickhouse_introspection$get_all_tables_in_all_dbs.invokeStatic(clickhouse_introspection.clj:125),	at metabase.driver.clickhouse_introspection$get_all_tables_in_all_dbs.invoke(clickhouse_introspection.clj:119),	at metabase.driver.clickhouse_introspection$fn__173076.invokeStatic(clickhouse_introspection.clj:170),	at metabase.driver.clickhouse_introspection$fn__173076.invoke(clickhouse_introspection.clj:166)
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