Previously chunks could be simultaneously created for the same
partition_id and a start_time and end_time of both NULL. This
prevents such bugs bug adding additional unique constraints and
locking the partition for chunk creation (as originally intended).
The chunk catalog table is now scanned with a native
scan rather than SPI call.
The scanner module is also updated with the option of
of taking locks on found tuples. In the case of chunk
scanning, chunks are typically returned with a share
lock on the tuple.
This patch refactors the code to use native heap/index scans for
finding partition epochs and partitions. It also moves the
partitioning-related code and data structures to partitioning.{c,h}.
There are two reasons for adding the partition count to
the partition_epoch table:
* It makes the partition_epoch more self-describing as
it makes it easy to see how many partitions are
in the current epoch as well as past ones.
* It simplifies native code that can read the partition
epoch, allocate memory for the right number of partitions,
and finally scan the partition table filling in each entry.
- Directory structure now matches common practices
- Regression tests now run with pg_regress via the PGXS infrastructure.
- Unit tests do not integrate well with pg_regress and have to be run
separately.
- Docker functionality is separate from main Makefile. Run with
`make -f docker.mk` to build and `make -f docker.mk run` to run
the database in a container.
