• Tom Lane's avatar
    Improve contrib/amcheck's tests for CREATE INDEX CONCURRENTLY. · b1f943d2
    Tom Lane authored
    Commits fdd965d07 and 3cd9c3b92 tested CREATE INDEX CONCURRENTLY by
    launching two separate pgbench runs concurrently.  This was needed so
    that only a single client thread would run CREATE INDEX CONCURRENTLY,
    avoiding deadlock between two CICs.  However, there's a better way,
    which is to use an advisory lock to prevent concurrent CICs.  That's
    better in part because the test code is shorter and more readable, but
    mostly because it automatically scales things to launch an appropriate
    number of CICs relative to the number of INSERT transactions.
    As committed, typically half to three-quarters of the CIC transactions
    were pointless because the INSERT transactions had already stopped.
    
    In passing, remove background_pgbench, which was added to support
    these tests and isn't needed anymore.  We can always put it back
    if we find a use for it later.
    
    Back-patch to v12; older pgbench versions lack the
    conditional-execution features needed for this method.
    
    Tom Lane and Andrey Borodin
    
    Discussion: https://postgr.es/m/139687.1635277318@sss.pgh.pa.us
    b1f943d2
PostgresNode.pm 65 KB