Re: [GENERAL] dropping role w/dependent objects

Tom Lane wrote:

> Perhaps a better solution is to keep MAX_REPORTED_DEPS where it is, and
> arrange that when it's exceeded, the *entire* list of dependencies gets
> reported to the postmaster log; we can expect that that will work.
> We still send the same just-the-count message to the client. We could
> add a hint suggesting to look in the postmaster log for the details.
> This would require some refactoring of checkSharedDependencies's API,
> I suppose, but doesn't seem especially difficult.

Attached is a patch to do something like that. Note that I made
checkSharedDependencies report the full list of dependencies by itself,
instead of passing it back to the caller. This can easily be changed if
considered too ugly.

I also removed the code that truncated the message when there were too
many entries, so that it reports MAX_REPORTED_DEPS to the client and
append "and other %d objects reported to the server log".

I think we can now reduce MAX_REPORTED_DEPS. Is 50 OK? Even 20 could
be reasonable. (Do we take a poll?)

This is the chance to comment to the wording, the approach or the
ugliness of API ...

Sample output to the client (note: in this test, MAX_REPORTED_DEPS is
set to 10).

foo=# drop user foo;
ERROR: role "foo" cannot be dropped because some objects depend on it
DETAIL: owner of tablespace foo
owner of table a100
owner of table a99
owner of table a98
owner of table a97
owner of table a96
owner of table a95
owner of table a94
owner of table a93
owner of table a92
5 objects in database bar
and other 95 objects reported to the server log
foo=#

Whereas the postmaster log gets

LOG: objects dependent on role foo
DETAIL: owner of tablespace foo
owner of table a100
owner of table a99
owner of table a98
owner of table a97
owner of table a96
owner of table a95
owner of table a94
owner of table a93
owner of table a92
owner of table a91
owner of table a90
owner of table a89
owner of table a88
owner of table a87
owner of table a86
owner of table a85
owner of table a84
owner of table a83
owner of table a82
owner of table a81
owner of table a80
owner of table a79
owner of table a78
owner of table a77
owner of table a76
owner of table a75
owner of table a74
owner of table a73
owner of table a72
owner of table a71
owner of table a70
owner of table a69
owner of table a68
owner of table a67
owner of table a66
owner of table a65
owner of table a64
owner of table a63
owner of table a62
owner of table a61
owner of table a60
owner of table a59
owner of table a58
owner of table a57
owner of table a56
owner of table a55
owner of table a54
owner of table a53
owner of table a52
owner of table a51
owner of table a50
owner of table a49
owner of table a48
owner of table a47
owner of table a46
owner of table a45
owner of table a44
owner of table a43
owner of table a41
owner of table a40
owner of table a39
owner of table a38
owner of table a37
owner of table a36
owner of table a35
owner of table a34
owner of table a33
owner of table a32
owner of table a31
owner of table a30
owner of table a29
owner of table a28
owner of table a27
owner of table a26
owner of table a25
owner of table a24
owner of table a23
owner of table a22
owner of table a21
owner of table a20
owner of table a19
owner of table a18
owner of table a17
owner of table a16
owner of table a15
owner of table a14
owner of table a13
owner of table a12
owner of table a11
owner of table a10
owner of table a9
owner of table a8
owner of table a7
owner of table a6
owner of table a5
owner of table a4
owner of table a3
owner of table a2
owner of table a1
owner of table a42
owner of table qux
owner of table baz
owner of table bar
owner of table foo
STATEMENT: drop user foo;

--
Alvaro Herrera http://www.CommandPrompt.com/
PostgreSQL Replication, Consulting, Custom Development, 24x7 support