Okay, this one might qualify as "Advanced" joining...

[Matt C]

Problem is that I can't really put all the details in here because of an
NDA. What's going on is that a query with multiple left joins is
apparently spooking mySQL. Server doesn't crash but I get:

"Query Failed:SELECT accounts.id as account_id.. LEFT JOIN ... LEFT JOIN
.... LEFT JOIN ..." (Big query is what I mean) "... amount DESC LIMIT 0,5

::MySQL error 2013: Lost connection to MySQL server during query"

I have never seen that error before (but I'm not a mysql pro). I wanted
to see what was up so I pasted the whole query into phpMyAdmin, and (!):

SQL query:
SHOW TABLE STATUS LIKE 'opportunities';

MySQL said: Documentation
#2006 - MySQL server has gone away

Ow. Don't go away, server! Don't leave me here! That line about TABLE
STATUS isn't actually in the query; something else is triggering it...

Thought it might be a version problem but I'm using 5.0.15 and doc says
the app is compatible with 5.0.x.

M

[Matt C]

I discovered that

#2006 - MySQL server has gone away

sometimes indicates packets are too big -- IMO the most likely suspect
among the things indicated at
http://dev.mysql.com/doc/refman/5.0/en/gone-away.html

I extended serverside to 5MB and clientside to 32MB

This error didn't occur every time, just part of the time, so I can't
say for sure this has "fixed" it.... will get back to ye.

M

[Matt C]

Matt C wrote:

I discovered that

#2006 - MySQL server has gone away

sometimes indicates packets are too big -- IMO the most likely suspect
among the things indicated at
http://dev.mysql.com/doc/refman/5.0/en/gone-away.html

I extended serverside to 5MB and clientside to 32MB

This error didn't occur every time, just part of the time, so I can't
say for sure this has "fixed" it.... will get back to ye.

M

running "check table" on the whole dB gives me a bunch of
PRIMARY and INDEX keys should not both be set for column `id`
and
More than one INDEX key was created for column `call_id`

and (bingo! (?)) :
"1 client is using or hasn't closed the table prope.."
for the table users_activity

so far it seems to be that table each time