[HACKERS] dollar quoting and pg_dump
I had a brief look at this today. Basically, I thought of adding a new routine to dumputils.c thus: void appendStringLiteralDQ(PQExpBuffer buf, const char *str, const char *dqprefix) and using it in dumping function bodies and comments on all objects, with a prefix argument of function and comment respectively. There might be other places where we want to use dollar quoting, but this would be a good start, ISTM. Basically, this routine would start with $ (+ dqprefix if not null) and then keep adding characters (in turn _1234567890) until that string was not found in str, then appending $ and using that as the delimiter. Thoughts? cheers andrew ---(end of broadcast)--- TIP 9: the planner will ignore your desire to choose an index scan if your joining column's datatypes do not match
Re: [HACKERS] dollar quoting and pg_dump
Andrew Dunstan [EMAIL PROTECTED] writes: ... using it in dumping function bodies and comments on all objects, with a prefix argument of function and comment respectively. There might be other places where we want to use dollar quoting, but this would be a good start, ISTM. Do we really need to be that verbose? Why not start with the minimal $$ and extend only if needed? On the KISS principle, trying $$, $X$, $XX$, $XXX$, etc seems sufficient. For that matter, I'm not convinced we should use $$ for comments. They don't have nearly the problem that functions do with embedded quotes. A thought: maybe just put this logic into the regular appendStringLiteral routine, and trigger it when the string contains any quotes or backslashes; if it has none, you can just use quotes ... BTW, I've been holding off making this change myself, realizing that it will completely break backwards compatibility of pg_dump output to 7.4 and earlier. Not sure if anyone is trying to use CVS tip pg_dump with older releases, but it seems possible given that the dump ordering issue is finally solved. Might be a good idea to make it disablable with a fallback to regular quoting. regards, tom lane ---(end of broadcast)--- TIP 2: you can get off all lists at once with the unregister command (send unregister YourEmailAddressHere to [EMAIL PROTECTED])
Re: [HACKERS] dollar quoting and pg_dump
Andrew Dunstan [EMAIL PROTECTED] writes: Tom Lane wrote: A thought: maybe just put this logic into the regular appendStringLiteral routine, and trigger it when the string contains any quotes or backslashes; if it has none, you can just use quotes ... I did think of fallback, but rejected it on the KISS principle :-) I also prefer consistency in style - I want all my functions dollar quoted even if they don't currently contain characters in need of escape. Good point. Never mind that idea then. Might be a good idea to make it disablable with a fallback to regular quoting. Makes sense. -X disable-dollar-quoting? Or we could have it turned off by default and require it to be specifically turned on - that might conform to the principle of least surprise, at least for now. I don't mind if it's on by default; just thinking that some people might appreciate a way to turn it off. -X disable-dollar-quoting sounds fine. regards, tom lane ---(end of broadcast)--- TIP 2: you can get off all lists at once with the unregister command (send unregister YourEmailAddressHere to [EMAIL PROTECTED])
Re: [HACKERS] dollar quoting and pg_dump
I don't mind if it's on by default; just thinking that some people might appreciate a way to turn it off. -X disable-dollar-quoting sounds fine. Does it _have_ to be dollars? Other languages call this feature 'heretext' IIRC. Chris ---(end of broadcast)--- TIP 3: if posting/reading through Usenet, please send an appropriate subscribe-nomail command to [EMAIL PROTECTED] so that your message can get through to the mailing list cleanly
Re: [HACKERS] dollar quoting and pg_dump
Christopher Kings-Lynne wrote: I don't mind if it's on by default; just thinking that some people might appreciate a way to turn it off. -X disable-dollar-quoting sounds fine. Does it _have_ to be dollars? Other languages call this feature 'heretext' IIRC. This is not heretext, and calling it such would be quite misleading. Nobody has yet come up with a better name for it. cheers andrew ---(end of broadcast)--- TIP 8: explain analyze is your friend
Re: [HACKERS] dollar quoting and pg_dump
On Wed, 24 Mar 2004, Christopher Kings-Lynne wrote: I don't mind if it's on by default; just thinking that some people might appreciate a way to turn it off. -X disable-dollar-quoting sounds fine. Does it _have_ to be dollars? Other languages call this feature 'heretext' IIRC. No, but I think the rough consensus was that the behavior of this feature is different enough from shell and Perl here documents that it deserved a different name. In particular the $ is part of both the opening and closing token, and newlines aren't relevant at either the beginning or end. Jon ---(end of broadcast)--- TIP 3: if posting/reading through Usenet, please send an appropriate subscribe-nomail command to [EMAIL PROTECTED] so that your message can get through to the mailing list cleanly
Re: [HACKERS] dollar quoting and pg_dump
Christopher Kings-Lynne [EMAIL PROTECTED] writes: Does it _have_ to be dollars? Other languages call this feature 'heretext' IIRC. I'm not in love with the name dollar quoting either ... but here text would be quite misleading. See the archives for the discussions that led us to develop our definition. The features that go by that name usually have dependencies on formatting (ie newline boundaries) that we specifically rejected. Right now would be a fine time to invent a better name if you can think of one ... regards, tom lane ---(end of broadcast)--- TIP 6: Have you searched our list archives? http://archives.postgresql.org
