Add support for Oracle
This makes it easier to identify the session on the Oracle side.
Fix crash or bad results with pushed down join queries.
The query target list can change during query planning, but oracle_fdw relied on the one from before.
This bug only manifests in PostgreSQL v11.
Bug found by @Jaime2ndQuadrant and fixed by @yamatattsu.
Fix push-down of foreign scan conditions with variables belonging to other tables.
This can lead to wrong results and warnings like:
WARNING: column number x of foreign table "y" does not exist in foreign Oracle table, will be replaced by NULL
Fix crash or bad results in queries with IN or
= ANYwhere the element type on the right-hand side is different from the left-hand side type.
Add support for reading infinite
Oracle NUMBER has infinite values, which are represented as
numericdoes not know infinity, map these values to
NaNin this case. For
double precisionwe can use the normal infinity values.