Get SQLite Manager . . . https://addons.mozilla.org/en-US/firefox/addon/sqlite-manager/ SQLite Manager / Tables / moz_places Right-click on moz_places / Reindex Table / Yes * * * * * * * * * * * * * * * * * * * * * * * * * Per this page . . . https://support.mozilla.org/en-US/questions/969977 The minimum file size of the places.sqlite file is 10 MB, and Firefox increases this file in 10 MB chunks when necessary (its size is never reduced when deleting history or bookmarks). This is done for performance issues caused by fragmentation. * * * * * * * * * * * * * * * * * * * * * * * * * . . . My places.sqlite is 10,240 KB (10 MB) * * * * * * * * * * * * * * * * * * * * * * * * * I was trying to figure out what: Index / Reindex Index . . . does I found that it only does something with this: Are you sure you want to perform the following operation(s): REINDEX "main"."moz_annos_placeattributeindex" SQL: REINDEX "main"."moz_annos_placeattributeindex" . . . what does Reindex Index do?