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SLAPD-BDB(5)
NAME
  slapd-bdb, slapd-hdb - Berkeley DB backends to slapd

SYNOPSIS
  /usr/internet/openldap/etc/slapd.conf

DESCRIPTION
  The bdb backend to slapd(8) is the recommended primary backend for a normal
  slapd database.  It uses the Sleepycat Berkeley DB (BDB) package to store
  data.	 It makes extensive use of indexing and caching to speed data access.

  hdb is a variant of the bdb backend that uses a hierarchical database
  layout which supports subtree renames. It is otherwise identical to the bdb
  behavior, and all the same configuration options apply.

  It is noted that these options are intended to complement Berkeley DB
  configuration options set in the environment's DB_CONFIG file.  See
  Berkeley DB documentation for details on DB_CONFIG configuration options.
  Where there is overlap, settings in DB_CONFIG take precedence.

CONFIGURATION
  These slapd.conf options apply to the bdb and hdb backend database.  That
  is, they must follow a "database bdb" or "database hdb" line and come
  before any subsequent "backend" or "database" lines.	Other database
  options are described in the slapd.conf(5) manual page.

  cachesize <integer>
       Specify the size in entries of the in-memory entry cache maintained by
       the bdb or hdb backend database instance.  The default is 1000
       entries.

  cachefree <integer>
       Specify the number of entries to free from the entry cache when the
       cache reaches the cachesize limit.  The default is 1 entry.

  checkpoint <kbyte> <min>
       Specify the frequency for checkpointing the database transaction log.
       A checkpoint operation flushes the database buffers to disk and writes
       a checkpoint record in the log.	The checkpoint will occur if either
       <kbyte> data has been written or <min> minutes have passed since the
       last checkpoint.	 Both arguments default to zero, in which case they
       are ignored. When the <min> argument is non-zero, an internal task
       will run every <min> minutes to perform the checkpoint.	See the
       Berkeley DB reference guide for more details.

  dbconfig <Berkeley-DB-setting>
       Specify a configuration directive to be placed in the DB_CONFIG file
       of the database directory. The dbconfig directive is just a
       convenience to allow all necessary configuration to be set in the
       slapd.conf file.	 The options set using this directive will only be
       written to the DB_CONFIG file if no such file existed at server
       startup time. This allows one to set initial values without
       overwriting/destroying a DB_CONFIG file that was already customized
       through other means. This directive may be specified multiple times,
       as needed. For example:
	       dbconfig set_cachesize 0 1048576 0
	       dbconfig set_lg_bsize 2097152

  dbnosync
       Specify that on-disk database contents should not be immediately
       synchronized with in memory changes.  Enabling this option may improve
       performance at the expense of data security.  See the Berkeley DB
       reference guide for more details.

  directory <directory>
       Specify the directory where the BDB files containing this database and
       associated indexes live.	 A separate directory must be specified for
       each database.  The default is /usr/internet/openldap/var/openldap-
       data.

  dirtyread
       Allow reads of modified but not yet committed data.  Usually
       transactions are isolated to prevent other operations from accessing
       uncommitted data.  This option may improve performance, but may also
       return inconsistent results if the data comes from a transaction that
       is later aborted.  In this case, the modified data is discarded and a
       subsequent search will return a different result.

  idlcachesize <integer>
       Specify the size of the in-memory index cache, in index slots. The
       default is zero. A larger value will speed up frequent searches of
       indexed entries. An hdb database needs a large idlcachesize for good
       search performance, typically three times the cachesize (entry cache
       size) or larger.

  index {<attrlist>|default} [pres,eq,approx,sub,<special>]
       Specify the indexes to maintain for the given attribute (or list of
       attributes).  Some attributes only support a subset of indexes.	If
       only an <attr> is given, the indices specified for default are
       maintained.  Note that setting a default does not imply that all
       attributes will be indexed. Also, for best performance, an eq index
       should always be configured for the objectClass attribute.

       A number of special index parameters may be specified.  The index type
       sub can be decomposed into subinitial, subany, and subfinal indices.
       The special type nolang may be specified to disallow use of this index
       by language subtypes.  The special type nosubtypes may be specified to
       disallow use of this index by named subtypes.  Note: changing index
       settings in slapd.conf(5) requires rebuilding indices, see
       slapindex(8); changing index settings dynamically by LDAPModifying
       "cn=config" automatically causes rebuilding of the indices online in a
       background task.

  linearindex
       Tell slapindex to index one attribute at a time. By default, all
       indexed attributes in an entry are processed at the same time. With
       this option, each indexed attribute is processed individually, using
       multiple passes through the entire database. This option improves
       slapindex performance when the database size exceeds the dbcache size.
       When the dbcache is large enough, this option is not needed and will
       decrease performance.  Also by default, slapadd performs full indexing
       and so a separate slapindex run is not needed. With this option,
       slapadd does no indexing and slapindex must be used.

  lockdetect {oldest|youngest|
       Specify which transaction to abort when a deadlock is detected.	The
       default is random.

  mode <integer>
       Specify the file protection mode that newly created database index
       files should have.  The default is 0600.

  searchstack <depth>
       Specify the depth of the stack used for search filter evaluation.
       Search filters are evaluated on a stack to accommodate nested AND / OR
       clauses. An individual stack is assigned to each server thread.	The
       depth of the stack determines how complex a filter can be evaluated
       without requiring any additional memory allocation. Filters that are
       nested deeper than the search stack depth will cause a separate stack
       to be allocated for that particular search operation. These
       allocations can have a major negative impact on server performance,
       but specifying too much stack will also consume a great deal of
       memory.	Each search stack uses 512K bytes per level. The default
       stack depth is 16, thus 8MB per thread is used.

  shm_key <integer>
       Specify a key for a shared memory BDB environment. By default the BDB
       environment uses memory mapped files. If a non-zero value is
       specified, it will be used as the key to identify a shared memory
       region that will house the environment.

ACCESS CONTROL
  The bdb and hdb backends honor access control semantics as indicated in
  slapd.access(5).

FILES
  /usr/internet/openldap/etc/slapd.conf
       default slapd configuration file

  DB_CONFIG
       Berkeley DB configuration file

SEE ALSO
  slapd.conf(5), slapd(8), slapadd(8), slapcat(8), slapindex(8), Berkeley DB
  documentation.

Index for Section 5

Alphabetical listing for S

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