[Java] Some questions about the metadata api of jdbc
- Dominant language
- Java
- Stars
- 94
- Forks
- 152
- Avg merge
- 3d 16h
- Merged PRs (30d)
- 11
Description
### Describe the usage question you have. Please include as many useful details as possible.
When I call the `getTables` interface, I get an error
```
java.sql.SQLException: Failed to transform VectorSchemaRoot.
at org.apache.arrow.driver.jdbc.ArrowFlightJdbcFlightStreamResultSet.executeForCurrentFlightStream(ArrowFlightJdbcFlightStreamResultSet.java:150)
at org.apache.arrow.driver.jdbc.ArrowFlightJdbcFlightStreamResultSet.execute(ArrowFlightJdbcFlightStreamResultSet.java:139)
at org.apache.arrow.driver.jdbc.ArrowFlightJdbcFlightStreamResultSet.fromFlightInfo(ArrowFlightJdbcFlightStreamResultSet.java:105)
at org.apache.arrow.driver.jdbc.ArrowDatabaseMetadata.getTables(ArrowDatabaseMetadata.java:902)
```
My server returns the result as follows
```
SELECT
TABLE_TENANT as TABLE_CAT,
TABLE_DATABASE as TABLE_SCHEM,
TABLE_NAME,
TABLE_TYPE
FROM
INFORMATION_SCHEMA.TABLES
WHERE TABLE_TENANT = 'cnosdb' AND TABLE_DATABASE LIKE 'public' AND TABLE_NAME LIKE '%' AND TABLE_TYPE IN ('TABLE')
ORDER BY
TABLE_TYPE, TABLE_CAT, TABLE_SCHEM, TABLE_NAME
```
By the code, I found that
- Convert `catalog_name` to `TABLE_CAT` in the `ArrowDatabaseMetadata.getCatalogs` api.
- Convert `db_schema_name` to `TABLE_SCHEM` in the `ArrowDatabaseMetadata.getSchemas` api.
- ......
For the above, can I think that the ResultSet Schema of my `getSchemas` implementation must be `db_schema_name`, `catalog_name` instead of `TABLE_SCHEM`, `TABLE_CATALOG`. The same goes for other API?
### Component(s)
Java
Contributor guide
Research direction
Start in ArrowDatabaseMetadata.getTables, getSchemas, and getCatalogs, then trace the schema transformation in ArrowFlightJdbcFlightStreamResultSet.executeForCurrentFlightStream. Compare the returned columns with the JDBC metadata contract and identify why the getTables result cannot be transformed. Done means documenting the expected schema and a confirmed resolution path.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- java
- Domain
- api, databases
- Issue type
- Bug
- Difficulty
- 4/5
- Estimated time
- 3-5 days
- Activity status
- Stale
- Clarity
- Needs clarification
- Newbie friendliness
- 25/100