feat: pg_dump support + schema evolution

[rebasedming]

Ticket(s) Closed

• Closes #

What

Implements the tableAM scan methods, which are used by the COPY to STDOUT command (invoked by pg_dump). Also handles ADD/DROP/RENAME column correctly.

How to test:

1. Inside cargo pgrx run, create a deltalake table.

CREATE TABLE t (a int, b text) USING deltalake;
INSERT INTO t VALUES (1, 'test'), (2, 'another');

2. Exit the connection and run a pg_dump

pg_dump -U <username> -d pg_analytics -h localhost -p 28816 > sample_db_backup.sql

Make sure the replace username with your username. This will create a dump of your database to sample_db_backup.sql.

3. Reconnect to the database and drop the table you just created.

DROP TABLE t;

4. Exit the connection and run the backup script

psql -U<username> -d pg_analytics -h localhost -p 28816 -f sample_db_backup.sql

5. Reconnect to the database to see the dropped table restored.

SELECT * FROM t;

Why

Enables users to back up deltalake tables with pg_dump.

How

Two changes:

1. Implemented the table AM scan functions, which are used by pg_dump to read from the table.
2. Fixed the way we were handling ALTER statements on deltalake tables to allow more statements to pass through the Postgres. Also enabled users to run ADD COLUMN over deltalake tables.

Tests

See new tests.

[codecov]

Codecov Report

Attention: 265 lines in your changes are missing coverage. Please review.

Comparison is base (87e7f25) 30.93% compared to head (73c4336) 0.00%.

Additional details and impacted files

@@            Coverage Diff             @@
##              dev    #837       +/-   ##
==========================================
- Coverage   30.93%   0.00%   -30.94%     
==========================================
  Files          84      45       -39     
  Lines        8060    4500     -3560     
==========================================
- Hits         2493       0     -2493     
+ Misses       5567    4500     -1067     

Files	Coverage Δ
pg_analytics/src/hooks/executor.rs	0.00% <0.00%> (ø)
pg_analytics/tests/basic.rs	0.00% <0.00%> (ø)
pg_analytics/src/errors.rs	0.00% <0.00%> (ø)
shared/src/fixtures/db.rs	0.00% <0.00%> (ø)
pg_analytics/src/hooks/process.rs	0.00% <0.00%> (ø)
pg_analytics/src/datafusion/datatype.rs	0.00% <0.00%> (ø)
pg_analytics/src/hooks/rename.rs	0.00% <0.00%> (ø)
pg_analytics/src/hooks/alter.rs	0.00% <0.00%> (ø)
pg_analytics/src/datafusion/schema.rs	0.00% <0.00%> (ø)
pg_analytics/src/tableam/scan.rs	0.00% <0.00%> (ø)

... and 45 files with indirect coverage changes