In LiteDB v5, pragmas are variables that can alter the behavior of a datafile. They are stored in the header of the datafile.
| Name | Read-only | Data type | Description | Default value |
|---|---|---|---|---|
| USER_VERSION | no | int | Reserved for version control by the user. Does not affect the behavior of the datafile. | 0 |
| COLLATION | yes (can be changed with a rebuild) | string (internally stored as int) | Check Collation. | CurrentCulture and IgnoreCase |
| TIMEOUT | no | int | Maximum amount of time (in seconds) that the engine waits for a shared resouce to be unlocked. | 60 |
| LIMIT_SIZE | no | long | Maximum size (in bytes) that the datafile can grow to. Cannot be smaller than the current datafile size. Cannot be smaller than 4 pages (32768 bytes). | long.MaxValue |
| UTC_DATE | no | bool | If false, dates are converted to local time on retrieval. Storage format is not affected (always in UTC). |
false |
| CHECKPOINT | no | int | Maximum number of pages to be stored in the log before a soft checkpoint. If set to 0, auto-checkpoint and shutdown checkpoint are disabled. |
1000 |
Examples
-
select pragmas from $database;returns the pragmas in the current datafile -
pragma USER_VERSION = 1;sets USER_VERSION to 1 -
pragma UTC_DATE = true;sets UTC_DATE to true
Rebuild Options
Rebuild options are used to configure a rebuild.
| Name | Data type | Description | Default value |
|---|---|---|---|
| collation | string | Check Collation. | null (will use CurrentCulture and IgnoreCase if null) |
| password | string | Defines the password for an encrypted datafile. | null (datafile will not be encrypted) |
If the rebuild command is issued without options, both are assumed to be null.
Rebuilds are also useful to defragment a datafile, making it smaller and faster to access.
rebuild;rebuilds the database with the default collation and no passwordrebuild {"collation": "en-GB/IgnoreCase"};rebuilds the datafile with theen-GBculture and case-insensitive string comparisonrebuild {"collation": "pt-BR/None", "password" : "1234"};rebuilds the datafile with thept-BRculture, case-sensitive string comparison and sets the password to “1234”