This commit improves the API of compress_chunk and decompress_chunk:
- have it return the chunk regclass processed (or NULL in the
idempotent case);
- mark it as STRICT
- add if_not_compressed/if_compressed options for idempotency
Add support for compress_chunks function.
This also adds support for compress_orderby and compress_segmentby
parameters in ALTER TABLE. These parameteres are used by the
compress_chunks function.
The parsing code will most likely be changed to use PG raw_parser
function.
Adds a move_chunk function which to a different tablespace. This is
implemented as an extension to the reorder command.
Given that the heap, toast tables, and indexes are being rewritten
during the reorder operation, adding the ability to modify the tablespace
is relatively simple and mostly requires adding parameters to the relevant
functions for the destination tablespace (and index tablespace). The tests
do not focus on further exercising the reorder infrastructure, but instead
ensure that tablespace movement and permissions checks properly occur.
New cluster-like command which writes to a new index than swaps,
much like is done for the data table, and only acquires
exclusive locks for said swap. This trades off disk usage for
lower contention: we hold locks for a much lower period of time,
allowing reads to work concurrently, but we have both the old
and new versions of the table existing at once, approximately
doubling storage usage while reorder is running.
Currently only works on chunks.
