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From:Paul DuBois Date:March 5 2003 1:00am
Subject:Re: Temporary Tables
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At 15:56 -0800 3/4/03, William R. Mussatto wrote:
>  > At 23:19 +0000 3/4/03, Mamatha Balasubramanian wrote:
>>>Thank you once again.
>>>
>>>I have a web-interface that does search on a given text and I would
>>>  have a script that creates a temporary table. So according to you,  in
>>>  my script, I just to need
>>>create a temporary table and not have to worry about another client
>>>  using the same web interface (and thereby using the same program).  Can
>>>  you please elaborate a little more on this?
>>
>>  Sure.
>>
>>  You are incorrect. :-)
>>
>>  That is, you're making an assumption that cannot necessarily be made. If
>>  you can guarantee that the web script will establish a new connection,
>>  and the connection will terminate when the script ends, you can indeed
>>  do what you describe above.
>>
>>  But you *cannot* do that if you're running your script in an environment
>>  that uses persistent connections that may be used by successive
>>  instances of the script.  PHP persistent connections fall into this
>>  class, for example.  Several requests might be served by the same
>>  instance of the web server process, and you don't know that one request
>>  won't be getting the connection used by a previous request.  In that
>>  case, the connection won't have closed, and the TEMPORARY table won't
>>  have disappeared.
>>
>>  You can guard against this by issuing this query before creating the
>>  TEMPORARY table:
>>
>>  DROP TABLE IF EXISTS tbl_name
>>
>>
>>>
>>>Thanks,
>>>Mamatha
>Probably even better to have the Drop Table at the end of the script that
>used it.

Not necessarily. If you create the table and then an error occurs,
you may not reach the point that drops the table.  Then the next
instance of the script, which expects the table not to exist when
it creates it, will fail.

Thread
Temporary TablesMamatha Balasubramanian5 Mar
  • Re: Temporary TablesPaul DuBois5 Mar
  • Re: Temporary TablesDaniel Kasak5 Mar
Re: Temporary TablesMamatha Balasubramanian5 Mar
  • Re: Temporary TablesPaul DuBois5 Mar
    • Re: Temporary TablesWilliam R. Mussatto5 Mar
      • Re: Temporary TablesPaul DuBois5 Mar
    • Re: Temporary TablesKH Chiu5 Mar
    • Re: Temporary TablesDaniel Kasak5 Mar
      • Re: Temporary TablesPaul DuBois5 Mar
Re: Temporary TablesMamatha Balasubramanian5 Mar