Making tasks in CI required before merging to master is important and
useful. The way this works is by saving the exact names of the required
tasks in the admin interface of the repo. It has a search box to add
them so it's not completely horrible, but doing so is quite a hassle
since we have so many jobs. So limiting the amount of churn in this list
of required jobs is quite useful.
This changes the names of tasks to only include the major versions of
Postgres, not the minor ones. Otherwise the next time we bump the minor
versions we would have to remove and re-add each of the jobs.
DESCRIPTION: This change starts a maintenance deamon at the time of
server start if there is a designated main database.
This is the code flow:
1. User designates a main database:
`ALTER SYSTEM SET citus.main_db = "myadmindb";`
2. When postmaster starts, in _PG_Init, citus calls
`InitializeMaintenanceDaemonForMainDb`
This function registers a background worker to run
`CitusMaintenanceDaemonMain `with `databaseOid = 0 `
3. `CitusMaintenanceDaemonMain ` takes some special actions when
databaseOid is 0:
- Gets the citus.main_db value.
- Connects to the citus.main_db
- Now the `MyDatabaseId `is available, creates a hash entry for it.
- Then follows the same control flow as for a regular db,
When debugging postgres it is quite hard to get to the source for
`errfinish` in `elog.c`. Instead of relying on the developer to set a
breakpoint in the `elog.c` file for `errfinish` for `elevel == ERROR`,
this change adds the breakpoint to `.gdbinit`. This makes sure that
whenever a debugger is attached to a postgres backend it will break on
postgres errors.
When attaching the debugger a small banner is printed that explains how
to disable the breakpoint.