PHP: Hypertext Preprocessor (original) (raw)

`A quick way to see which DBA handlers, without version numbers, that have been built into your version of MySQL on your system, use var_dump with dba_handler() as follows:

Many distros build in these DBA Handlers by default:
array(5) { [0]=> string(3) "cdb" [1]=> string(8) "cdb_make" [2]=> string(3) "db4" [3]=> string(7) "inifile" [4]=> string(8) "flatfile" }

using print and pre tags for readability:

array(5) {

[0]=>

string(3) "cdb"

[1]=>

string(8) "cdb_make"

[2]=>

string(3) "db4"

[3]=>

string(7) "inifile"

[4]=>

string(8) "flatfile"

}

Note there are issues with dba_insert and dba_replace without building for either GDBM or QDBM.
Here are two sources for the list of DBA handlers: (http://www.php-editors.com/php_manual/ref.dba.html and http://dewa03.unep.org/manuals/php_manual/ref.dba.html; )

CDBM & CDB compiles have issues with updates, you can read databases and write new database files, but you will be prevented from using dba_replace() and you may have issues with dba_insert().

NDBM & DBM are depreciated.

DB2, DB3 & DB4 (Berkeley DB Sleepycat Software / Oracle) Have read online about issues with dba_replace() and db4 specifically. Make sure you test your installation for correct usage of all DBA functions.

SDBM, TDB, TinyCDB were not listed on most of the sources I have found online. Those DBA handlers and the names of the developers were listed on the QDBM source forge site. How they interact with dba_replace() I do not know. You should be aware of their existence.

GDBM and QDBM are the only other two DBA handlers I am aware of. Both are reported to allow PHP's dba_replace() function to work correctly so either may be an acceptable option. The following three restrictions of traditional DBM are not issues for either GDBM or QDBM: 1) a process can handle only one database; 2) the size of a key and a value is bounded; 3) a database file is sparse.

DBA handler benchmark compares QDBM, GDBM, NDBM, SDBM, TDB, CDB, BDB, QDBM-BT-ASC, QDBM-BT-RND, BDB-BT-ASC, BDB-BT-RND can be found here: (http://qdbm.sourceforge.net/benchmark.pdf);

QDBM seems to offer significant improvements in speed over the other DBA Handlers, test in your environment to verify the results.

`