Stefan Kaltenbrunner wrote: > Jan Wieck wrote: > >> On 7/11/2006 12:43 PM, Christopher Browne wrote: >> >> >>> I have set up tarballs for a first release candidate; Jan should be >>> uploading those soon, and I'll see about updating the web site when they >>> are uploaded... >>> >> I have run them through a compile and a few tests and uploaded them to >> the usual location at >> >> http://developer.postgresql.org/~wieck/slony1/download/ >> >> One thing I wanted to discuss is related to a recent discussion on the >> hackers mailing list with respect to possible btree corruption due to >> xxid not being suitable. With a single origin setup, there is not >> problem during normal operation. But even then, any failover of move set >> could immediately cause the btree on the xid only (not the one on >> node-id, xid) to corrupt. I remember that this index was added because >> of the backend failure to use the one with the node-id. But that IMO >> doesn't warrant the risk of corrupting the index at the very time there >> is already trouble in the house (move set or failover isn't done because >> it is such a boring day). >> > > there is another issue with the current code - while it compiles and > works fine against postgresql -HEAD with standards_conforming_strings = > off(the default) it will silently corrupt data with > standards_conforming_strings = on. > The reason for this is the rather ad-hoc quoting in slon_quote_literal() > - it will for example double-escape '\\' in strings leading to > regression failures with for example testddl. > Maybe we should take a look at the new escaping functions in the recent > postgresql releases to make that more safe and future proof ? > Looking at src/include/c.h, it looks as though escape_backslash may be a backend control for this...
/* * Support macros for escaping strings. escape_backslash should be TRUE * if generating a non-standard-conforming string. Prefixing a string * with ESCAPE_STRING_SYNTAX guarantees it is non-standard-conforming. * Beware of multiple evaluation of the "ch" argument! */ #define SQL_STR_DOUBLE(ch, escape_backslash)^I\ ^I((ch) == '\'' || ((ch) == '\\' && (escape_backslash))) #define ESCAPE_STRING_SYNTAX^I'E' Is it possible that the resolution is to wrap Slony-I "quoted stuff submission" code with: int OldEsc; OldEsc = escape_backslash; escape_backslash = TRUE; [do bunch of stuff] escape_backslash = OldEsc; ???? That is the same sort of logic now used with DateStyle (where we keep the old value, and while writing dates, set it to the ISO conformant form...). _______________________________________________ Slony1-general mailing list [email protected] http://gborg.postgresql.org/mailman/listinfo/slony1-general
