configure olcDbMultival in default configuration

[davidcoutadeur]

It would be interresting to use the olcDbMultival option for attributes containing potentially many values.

See: https://www.openldap.org/doc/admin25/slapdconf2.html

5.2.7.9. olcDbMultival: { <attrlist> | default } <integer> hi,<integer> lo

Specify the number of values for which a multivalued attribute is stored in a separate table. Normally entries are stored as a single blob inside the database. When an entry gets very large or contains attributes with a very large number of values, modifications on that entry may get very slow. Splitting the large attributes out to a separate table can improve the performance of modification operations. The threshold is specified as a pair of integers. If the number of values exceeds the hi threshold the values will be split out. If a modification deletes enough values to bring an attribute below the lo threshold the values will be removed from the separate table and merged back into the main entry blob. The threshold can be set for a specific list of attributes, or the default can be configured for all other attributes. The default value for both hi and lo thresholds is UINT_MAX, which keeps all attributes in the main blob.

In addition to increasing write performance of operations the use of multival can also decrease fragmentation of the primary MDB database.

The goal is set this option for member and uniquemember in config-template-*