Kevin Grittner wrote:
> Management has simply given a mandate that the software be independent
> of OS and database vendor, and to use Java to help with the OS independence.
> ... we write all of our queries in ANSI SQL in our own query tool, parse it,
> and generate Java classes to run it.
A better solution, and one I've used for years, is to use OS- or database-specific features, but carefully encapsulate them in a single module, for example, "database_specific.java".
For example, when I started supporting both Oracle and Postgres, I encountered the MAX() problem, which (at the time) was very slow in Postgres, but could be replaced by "select X from MYTABLE order by X desc limit 1". So I created a function, "GetColumnMax()" that encapsulates the database-specific code for this. Similar functions encapsulate and a number of other database-specific optimizations.
Another excellent example: I have a function called "TableExists(name)". To the best of my knowledge, there simply is no ANSI SQL for this, so what do you do? Encapsulate it in one place.
The result? When I port to a new system, I know exactly where to find all of the non-ANSI SQL. I started this habit years ago with C/C++ code, which has the same problem: System calls are not consistent across the varients of Unix, Windows, and other OS's. So you put them all in one file called "machine_dependent.c".
Remember the old adage: There is no such thing as portable code, only code that has been ported.
In response to
pgsql-performance by date
|Next:||From: firstname.lastname@example.org||Date: 2007-04-03 22:13:15|
|Subject: SCSI vs SATA|
|Previous:||From: Alex Deucher||Date: 2007-04-03 21:43:47|
|Subject: Re: postgres 7.4 vs 8.x redux: query plans|
pgsql-hackers by date
|Next:||From: 4wheels||Date: 2007-04-04 00:37:27|
|Subject: Finding Queries that have been done on a DB|
|Previous:||From: Tom Lane||Date: 2007-04-03 20:51:33|
|Subject: Re: "Garbled" postgres logs |