On 2/16/15 9:43 PM, Kyotaro HORIGUCHI wrote:
Hello, I had a look on gram.y and found other syntaxes using WITH
option clause.
At Wed, 11 Feb 2015 14:34:17 -0600, Jim Nasby<jim.na...@bluetreble.com> wrote
in<54dbbcc9.1020...@bluetreble.com>
>I suspect at least some of this stems from how command line programs
>tend to process options before arguments. I tend to agree with you
>Tom, but I think what's more important is that we're consistent. COPY
>is already a bit of an oddball because it uses WITH, but both EXPLAIN
>and VACUUM use parenthesis immediately after the first
>verb. Introducing a parenthesis version that goes at the end instead
>of the beginning is just going to make this worse.
>
>If we're going to take a stand on this, we need to do it NOW, before
>we have even more commands that use ().
>
>I know you were worried about accepting options anywhere because it
>leads to reserved words, but perhaps we could support it just for
>EXPLAIN and VACUUM, and then switch to trailing options if people
>think that would be better.
I agree with the direction, but I see two issues here; how many
syntax variants we are allowed to have for one command at a time,
and how far we should/may extend the unified options syntax on
other commands.
Let me put the issues aside for now, VACUUM can have trailing
options naturally but it seems to change, but, IMHO, EXPLAIN
should have the target statement at the tail end. Are you
thinking of syntaxes like following?
VACUUM [FULL] [FREEZE] ... [ANALYZE] [tname [(cname, ...)]
| VACUUM [({FULL [bool]|FREEZE [bool]|...}[,...])] [tname [(cname, ...)]
| VACUUM [tname [(cname, ...)] [[WITH ]({FULL [bool]|FREEZE [bool]|...})]
REINDEX [{INDEX|TABLE|...}] name [[WITH] (VERBOSE [bool]|...)]
EXPLAIN [[WITH] ({ANALYZE [bool]|VERBOSE [bool]|... [,...]})] <statement>
For concrete examples, the lines prefixed by asterisk are in new
syntax.
If I could choose only one for explain, I would find it easier to be up
front. That way you do the explain part on one line and just paste the
query after that.
VACUUM FULL table1;
VACUUM ANALYZE table1 (col1);
VACUUM (ANALYZE, VERBOSE) table1 (col1);
*VACUUM table1 WITH (FREEZE on)
*VACUUM table1 (cola) WITH (ANALYZE)
*VACUUM table1 WITH (ANALYZE)
*VACUUM table1 (FREEZE on)
The fifth example looks quite odd.
I don't think we need to allow both () and WITH... I'd say one or the
other, preferably ().
--
Jim Nasby, Data Architect, Blue Treble Consulting
Data in Trouble? Get it in Treble! http://BlueTreble.com
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