Many questions

From: raptor <raptor(at)unacs(dot)bg>
To: "'pgsql-sql(at)postgresql(dot)org'" <pgsql-sql(at)postgresql(dot)org>
Subject: Many questions
Date: 1999-09-29 18:56:55
Message-ID: 37F260F7.920D67DB@unacs.bg
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hi,

I have several quesions.

1. Does $dbh->prepare_cached has some impact on performance for
PostgresSQL ? I read the TODO of mod_perl docs :"). But there is
discussion only for MySQL & Oracle.

2. Is this the right way to make transactions with DBI :

eval
{
local $h->{RaiseError} = 0 if $h->{RaiseError};
local $h->{AutoCommit} = 0 if $h->{AutoCommit};
.... do something SELECT, INSERT, UPDATE ....
}
if ($@) {$dbh->rollback}
else {$dbh->commit};

after it RaiseError & AutoCommit has their default values ?

3. Is it a good idea at the end of the script to clear the hash - in a
perspective of mod_perl. The hash may become very large ?
--> %hash = ();

HINT : try this to see memory usage of httpd deamons including SHARED
memory. You can't see it with "ps".

top -b -n 1 | grep -e "httpd\|PID" | cut -b '0-5,24-40'

4. What is the best way to implement something like NextPage, PrevPage
(+PageSize) for the DBI query.
Something like ADO/IIS similar methods.
SELECT ... LIMIT,OFFSET ... stuff ?!?!

5. At the moment I'm using global.asa (ASP.pm) to store some sub's that
I use in most of my pages. Is that the right way to do this ? Examples.

6. I saw that the :

CREATE UNIQUE INDEX xx ON yy (col1,col2);

is different from :
CREATE UNIQUE INDEX xx ON yy (col1);
CREATE UNIQUE INDEX xx ON yy (col2);

is the same true for CREATE INDEX (not unique). Is there way to make
UNIQUE case insensitive.

7. How to drop all indexes at once ?

Thanx
=====
iVAN
raptor(at)unacs(dot)bg
=====

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