The following is a list of Commerce search/solr fixes that you should consider installing. You can get these from the Commerce Support team:
Feature Pack 7:
JR50553.fep - Feature Pack 7 Cumulative1 Interim Fix
JR50553.fp - Fix Pack 8 Cumulative1 Interim Fix
JR50745.fep - resolves errors with replication timing and logic when using an inventory index.
Feature Pack 6:
JR49932 & JR49587- Cumulative fix , plus custom price facet fix & fast flow configuration fix
JR49759 - Memory leak on search server - searchers not closing
JR48954 - Products are not sequenced properly when a deep search is being performed on a given category
JR47012 - Running di-preprocess with multithread set to 'true' always reports success
JR49048 - Add a retry parameter to di-buildindex utility for checking the index status
JR50052 - Improve performance of query SELECT_FACET_VALUE_IMAGE_AND_SEQUENCE
JR49929.fep - provide more fine grained caching of facet data
Only needed if using inventory index:
JR49109 - Fields from the inventory index cannot be returned in conjunction with spellcheck.collate
JR49576 - Inventory Index does not return fields using 'fl' parameter from solr queries
Feature Pack 5:
JR47273 - Latest WebSphere Commerce Search cumulative iFix in v7 Feature Pack 5
JR47295 - Search performance enhancements bundle ( Fix Pack co-requisite for JR47273)
JR46691 - WebSphere Commerce Search cumulative iFix in v7 Feature Pack 5
JR47018 - Makes synonym expansion for AND type search more compact
JR50052 - Improve performance of query SELECT_FACET_VALUE_IMAGE_AND_SEQUENCE
JR49929.fep - provide more fine grained caching of facet data
Only needed if you use Oracle DB:
JR44514 - allow search utilities to run with Oracle RAC database
JR44616 - remove the schema name from the TI_DELTA_CATGROUP index name