SQL: correctness of SYS TABLES/COLUMNS results

[elasticmachine]

Original comment by @costin:

The two major meta calls in JDBC and ODBC for discovery are get tables and get columns.
The latter in particular tends to be important as it describes a column type and properties through 18 fields in LINK REDACTED) and 24 in LINK REDACTED.

While JDBC ignores most of them, ODBC does not. This issue is about checking that the values returns properly describe the types and obey the ODBC spec - for example fields like SQL_DATETIME_SUB are not returned properly.
This ties also into type info (LINK REDACTED and LINK REDACTED).

P.S. This issue is not urgent - rather acts as a reminder.

[elasticmachine]

Original comment by @bpintea:

The return value in UNSIGNED_ATTRIBUTE column should be set to false for numeric values, since they are actually signed in ES.

[elasticmachine]

Original comment by @bpintea:

'SYS COLUMNS' should not return null in BUFFER_LENGTH column.

[elasticmachine]

Original comment by @costin:

@bpintea okay but what should be the value for BUFFER_LENGTH then?

[elasticmachine]

Original comment by @costin:

@bpintea There's no column UNSIGNED_ATTRIBUTE defined in either columns or tables. I've looked at the ODBC spec for columns LINK REDACTED and couldn't find it there either.

[elasticmachine]

Original comment by @bpintea:

Just to note, the UNSIGNED_ATTRIBUTE comment was assigned incorrectly to this ticket, it concerns the correctness of SYS TYPES resultset.

[costin]

Addressed by #30530, #30418, #30516 (and several others in the old repo)