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Entry  17 Jan 2009, Konstantin Olchanski, Info, mhttpd, mlogger updates 
    Reply  21 Jan 2009, Andreas Suter, Bug Report, mhttpd, mlogger updates 
    Reply  18 Feb 2009, Konstantin Olchanski, Info, odbc sql history mlogger update 
Message ID: 562     Entry time: 18 Feb 2009     In reply to: 555
Author: Konstantin Olchanski 
Topic: Info 
Subject: odbc sql history mlogger update 
> mhttpd and mlogger have been updated with potentially troublesome changes.
> These new features are now available:
> - a "feature complete" implementation of "history in an SQL database".

The mlogger SQL history driver has been updated with improvements that make this new system usable in 
production environment: the silly "create all tables on startup, every time, even if they already exist" is fixed,
mlogger survives restarts of mysqld and checks that existing sql columns have data types compatible with the 
data we are trying to write.

There are still a few trouble spots remaining. For example, in mapping midas names into sql names (sql names 
have more restrictions on permitted characters) and in reverse mapping of sql data types to midas data types. 
To properly solve this, I may have to save the midas names and data types into an additional index table.

Included is the mh2sql utility for importing existing history files into an SQL database (in the same way as if 
they were written into the database by mlogger).

The mhttpd side of this system still needs polishing, but should be already fully functional.

A preliminary version of documentation for this new SQL history system is here. After additional review and 
editing it will be committed to the midas midox documentation. Included are full instructions on enabling 
writing of midas history into a MySQL database.
http://ladd00.triumf.ca/~olchansk/midas/Internal.html#History_sql_internal

svn revision 4452
K.O.
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