dba_handlers

(PHP 4 >= 4.3.0, PHP 5)

dba_handlers — Listar todos los gestores disponibles

Descripción

array dba_handlers ([ bool $full_info = false ] )

dba_handlers() lista todos los gestores soportados por esta extensión.

Parámetros

full_info: Activa/desactiva la mostración de la información completa en el resultado.

Valores devueltos

Devuelve un array de gestores de bases de datos. Si full_info está establecido a TRUE, el array será asociativo con los nombres de los gestores como claves y la información de su versión com valor. De otro modo, el resultado será un array indexado de nombres de gestores.

Nota:
Cuando se usa la biblioteca cdb interna verá cdb y cdb_make.

Ejemplos

Ejemplo #1 Ejemplo de dba_handlers()


<?php

echo "Gestores de DBA disponibles:\n";
foreach (dba_handlers(true) as $nombre_gestor => $versión_gestor) {
  // limpiar las versiones
  $versión_gestor = str_replace('$', '', $versión_gestor);
  echo " - $nombre_gestor: $versión_gestor\n";
}

?>

El resultado del ejemplo sería algo similar a:

Gestores de DBA disponibles:
 - cdb: 0.75, Revision: 1.3.2.3 
 - cdb_make: 0.75, Revision: 1.2.2.4 
 - db2: Sleepycat Software: Berkeley DB 2.7.7: (08/20/99)
 - inifile: 1.0, Revision: 1.6.2.3 
 - flatfile: 1.0, Revision: 1.5.2.4

add a note User Contributed Notes dba_handlers - [1 notes]

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cbemerine at gmail dot com ¶

3 years ago


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: 



<?php

var_dump ( "dba_handlers()" ); 

?>



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.

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