Bruce Momjian <pgman(at)candle(dot)pha(dot)pa(dot)us> writes:
> In the current sources, analyze allows read-access. I don't think
> vacuum allows any other access because the rows are moving in the file.
VACUUM *must* have exclusive lock.
ANALYZE actually is only a reader (AccessShareLock) and does not lock
out either reading or writing in current sources.
regards, tom lane