Benchmark test:
http://qdbm.sourceforge.net/benchmark.pdf
XXI. Database (dbm-style) Abstraction Layer Functions简介These functions build the foundation for accessing Berkeley DB style databases. This is a general abstraction layer for several file-based databases. As such, functionality is limited to a common subset of features supported by modern databases such as Sleepycat Software's DB2. (This is not to be confused with IBM's DB2 software, which is supported through the ODBC functions.) 需求The behaviour of various aspects depends on the implementation of the underlying database. Functions such as dba_optimize() and dba_sync() will do what they promise for one database and will do nothing for others. You have to download and install supported dba-Handlers. 表格 1. List of DBA handlers
When invoking the dba_open() or dba_popen() functions, one of the handler names must be supplied as an argument. The actually available list of handlers is displayed by invoking phpinfo() or dba_handlers(). 安装By using the --enable-dba=shared configuration option you can build a dynamic loadable module to enable PHP for basic support of dbm-style databases. You also have to add support for at least one of the following handlers by specifying the --with-XXXX configure switch to your PHP configure line.
表格 2. Supported DBA handlers
运行时配置本扩展模块在 php.ini 中未定义任何配置选项。 资源类型The functions dba_open() and dba_popen() return a handle to the specified database file to access which is used by all other dba-function calls. 预定义常量本扩展模块未定义任何常量。 范例
DBA is binary safe and does not have any arbitrary limits. However, it inherits all limits set by the underlying database implementation. All file-based databases must provide a way of setting the file mode of a new created database, if that is possible at all. The file mode is commonly passed as the fourth argument to dba_open() or dba_popen(). You can access all entries of a database in a linear way by using the dba_firstkey() and dba_nextkey() functions. You may not change the database while traversing it.
add a note
User Contributed Notes
doppelbauer at gmail dot com
14-Oct-2006 10:47
Benchmark test:
jason
21-Dec-2004 11:33
Don't make the dumb mistake I did, if you copy the first example at the top and modify it for test, the dba_open specifies "n" which will truncate the database that you are pointing to. Make sure you change it to "r" if you just want to read from an existing dbm file.
kevinphpdotnet at stormtide dot ca
18-Mar-2004 03:10
When using db4 on redhat 7.3 you may get signal 11s on the apache child processes. The installation test scripts will report that db4 is working correctly as the cli will not sig 11 out. The solution is to check to see if mod_rewrite is installed with apache, if it is either dereference it from libdb.so.3 or build apache without mod rewrite. Once this is done you will no longer have your child processes dying out and db4 will work. If you do not get a sig 11 after dba_open just ignore this comment.
djm at web dot us dot uu dot net
18-Oct-1999 06:28
With db2, you need to call dba_sync() to get the data written to disk; the examples are missing this. db2 uses
| ||||||||||||||||||||||||||||||||||||||||||||||||||||