This change seems necessary in conjunction with long queries, and it
cleans up some bogosity in connection with long EXPLAIN texts anyway.
Note that current libpq will accept any length error message (at least
until it runs out of memory); prior versions have a limit of 8K, but
will cleanly discard excess error text, so there shouldn't be any
big compatibility problems with old clients.
this one could be useful for people experiencing out-of-memory crashes while
executing queries which retrieve or use a very large number of tuples.
The problem happens when storage is allocated for functions results used in
a large query, for example:
select upper(name) from big_table;
select big_table.array[1] from big_table;
select count(upper(name)) from big_table;
This patch is a dirty hack that fixes the out-of-memory problem for the most
common cases, like the above ones. It is not the final solution for the
problem but it can work for some people, so I'm posting it.
The patch should be safe because all changes are under #ifdef. Furthermore
the feature can be enabled or disabled at runtime by the `free_tuple_memory'
options in the pg_options file. The option is disabled by default and must
be explicitly enabled at runtime to have any effect.
To enable the patch add the follwing line to Makefile.custom:
CUSTOM_COPT += -DFREE_TUPLE_MEMORY
To enable the option at runtime add the following line to pg_option:
free_tuple_memory=1
Massimo
the gettimeofday doesn't compile under Linux with glibc2 because
the DST_NONE constant is no more defined. It seems that this code
(written by me) has always be wrong but for some reason working.
From: Massimo Dal Zotto <dz@cs.unitn.it>
-d4 now prints compressed trees from nodeToString()
-d5 prints pretty trees via nodeDisplay()
new pg_options: pretty_plan, pretty_parse, pretty_rewritten
Jan
DataDir is set after read_pg_options if postgres is called
interactively. If postgres is forked by postgres DataDir is read from
the PGDATA enviromnent variable set by the postmaster and this explains
while the bug disappears. I have written this patch but I don't like
it. Any better idea?
Massimo Dal Zotto
before.
> Looks like a GNU-ism. I nice one, but still a GNU-ism.
Sorry, I didn't know it is a GNU extension. I have written this patch
which should fix the problem. Let me know if you still have problems.
Massimo Dal Zotto
