Parameter Configuration

Halo database parameters are primarily configured through the parameter file (default: $PGDATA/postgresql.conf).

vi $PGDATA/postgresql.conf

Parameter Types

All parameter names are case-insensitive. Each parameter can accept values of one of the following five types:

• Boolean: Values can be written as on/off, true/false, yes/no, 1/0
• String: Values are typically enclosed in single quotes; any single quotes within the value must be escaped
• Numeric: Accepts hexadecimal (starting with 0x) and decimal values; thousand separators are not allowed
• Numeric with units: Available memory units are B (bytes), kB (kilobytes), MB (megabytes), GB (gigabytes), with a multiplier of 1024; available time units are us (microseconds), ms (milliseconds), s (seconds), min (minutes), h (hours), and d (days)
• Enum: Specified in the same way as string parameters, but limited to a finite set of values. Available values can be found in pg_settings.enumvals

Parameter Effect Timing

Depending on the nature and function of parameters, the timing of when parameter settings take effect varies:

• Effective at startup: Requires a restart of the database instance to take effect
• Effective during runtime: Can be reloaded via the SIGHUP signal; execute pg_ctl reload to take effect
• Read-only parameters: Cannot be changed

The effect timing for each parameter is noted at the end of its description in this chapter.