citus_shard_sizes view had a shard name column we use to extract shard
id. This PR changes the column to shard id so we don't do unnecessary
string operation.
Changes test files in multi and multi-1 schedules such that they
accomodate coordinator in metadata.
Changes fall into the following buckets:
1. When coordinator is in metadata, reference table shards are present
in coordinator too.
This changes test outputs checking the table size, shard numbers etc.
for reference tables.
2. When coordinator is in metadata, postgres tables are converted to
citus local tables whenever a foreign key relationship to them is
created. This changes some test cases which tests it should not be
possible to create foreign keys to postgres tables.
3. Remove lines that add/remove coordinator for testing purposes.
DESCRIPTION: Correctly report shard size in citus_shards view
When looking at citus_shards, people are interested in the actual size
that all the data related to the shard takes up on disk.
`pg_total_relation_size` is the function to use for that purpose. The
previously used `pg_relation_size` does not include indexes or TOAST.
Especially the missing toast can have enormous impact on the size of the
shown data.
* Reimplement citus_update_table_statistics
* Update stats for the given table not colocation group
* Add tests for reimplemented citus_update_table_statistics
* Use coordinated transaction, merge with citus_shard_sizes functions
* Update the old master_update_table_statistics as well