Optimizing Searches

This section contains these topics:

• Optimizing Searches for Large Group Entries

• Optimizing Searches for Skewed Attributes

Optimizing Searches for Large Group Entries

Searches for group entries with more than a few thousand values for either the member or uniquemember attribute can have high latency. If you find unacceptably high latency in searches for large group entries with attributes other than member and uniquemember, then do the following:

1. Set the orclindexhints attribute to 1 in the dsaconfig entry. For example, on UNIX, enter the following:

   ldapmodify -D "cn=orcladmin" -w <passwd> -h ldaphost -p ldapport <<!
   dn: cn=dsaconfig,cn=configsets,cn=oracle internet directory
   changetype: modify
   replace: orclindexhints
   orclindexhints: 1
   !
   
   

2. Login to the Oracle Internet Directory database as the ODS user and execute $ORACLE_HOME/ldap/admin/oidbmind.sql. This creates two bitmap indexes on the ds_attrstore table instead of one B-tree index.

3. Restart the Oracle directory server.

   Optimizing Searches for Skewed Attributes

   To service a typical search request, the directory server sends a SQL statement to the Oracle9i Database Server. If a given attribute has very different response times depending on its value, then the attribute is said to be skewed. For example, if searches for my_attribute=value1 and my_attribute=value2 have very different response times, then my_attribute is said to be a skewed.

   You can uniform the response times for searches for such an attribute by adding it as a value of the orclskewedattribute attribute, which is in the dsaconfig entry. The DN of the dsaconfig entry is cn=dsaconfig,cn=configsets,cn=oracle internet directory.

   By default, the objectclass attribute is listed as a value in the orclskewedattribute attribute.

   Optimizing Searches for Skewed Attributes by Using Oracle Directory Manager

   To optimize queries to the database:

   1. In the navigator pane, expand Oracle Internet Directory Servers and select the directory server instance.

   2. In the right pane, select the Query Optimization tab. The fields in the Query Optimization tab page are listed and described in Table C-36.

   3. In the Query Optimization tab page, in the Attributes with Low Cardinality field, enter the attributes you want to designate as skewed.

   4. Choose Apply.

   Optimizing Searches for Skewed Attributes by Using ldapmodify

   To optimize the search for a skewed attribute, you use ldapmodify to add it as a value of the orclskewedattribute attribute.

   For example, to add my_attribute to the orclskewedattribute attribute, you would enter the following:

   ldapmodify -D "cn=orcladmin" -w password -h host -p port <<!
   dn: cn=dsaconfig,cn=configsets,cn=oracle internet directory
   changetype: modify
   add: orclskewedattribute
   orclskewedattribute: my_attribute
   !