1. If necessary, connect to an HFSQL server and display the description of one of the databases or data files (double-click on the name of the database or data file in the tree structure).
2. In the ribbon, click on "Optimize and repair". The optimization window appears.
   
3. Specify options.
4. Start data file optimization.

Setting optimization options

• Check indexes Checks consistency between index and data files.
• Optimize speed of indexes (recalculate statistics) Optimizes indexes by calculating index statistics. These statistics are used to optimize the filters, the queries and the HFSQL views.
  Note: The more the data file is modified, the less the statistics reflect the content of the HFSQL data file.. The more records the data file contains, the less the modification of a single record impacts the overall statistics.
• Rebuild indexes (standard + full-text) Optimizes access to data file records and recalculates statistics. All the crossed records are automatically deleted. If this option is enabled, the following advanced parameter options can be selected.
• Rebuild indexes and fix damaged memos Optimizes the entire data file, its index and memos. If this option is enabled, advanced parameter options can be selected.
• Compact memos Optimizes the entire data file, its index and memos. The memos will be compressed.
  Remarks:
  • The data file is recreated: the last write date of the last record (obtained by function HRecordDate) is reset to the current date.
  • Timestamp items are also modified and are set to the date and time at which the optimization is performed.

• With the exception of the "Optimize speed of indexes (recalculate statistics)" option, all optimization modes cause data files to be blocked during optimization. The users are informed that the data file is currently under maintenance.
• Once the reindexing is performed, the current HFSQL context is restored (except if the option for compressing memos was chosen).

Advanced reindexing parameters

• Delete damaged records
  If this option is checked, the damaged records are automatically deleted.
• Delete inactive records (deleted or crossed records)
  If this option is selected, the crossed records are permanently deleted.
  Reminder: When a record is crossed out, it is logically deleted and may be recovered later.. The record is still found in the data file. Deleting the crossed records deletes these records permanently and optimizes the size of data file.
• Density of the index
  Corresponds to the density rate of the indexes. This rate is set to 80 by default.
  A higher rate increases the density of the index and reduces its size. In this case, the browses, searches, filters and queries are faster. The additions of records and the modifications of records may be slower.
  A smaller rate reduces the density of the index and increases its size. In this case, iterations, searches, filters and queries will be slower. The additions of records and the modifications of records will be faster.
  Please note: this parameter can only be used on data files in HFSQL Classic or Client/Server format.
• Charset
  The character set of the data file is kept by default. However, a re-indexing operation can be performed by changing the character set of the data file. In this case, the new character set will be taken into account during the re-index operation. Sorts (or searches) on string keys (strings, characters, date and time) will be performed according to this character set.