Interface ICreateBTreeIndexOptionsSyntax
B-tree index options
Inherited Members
Namespace: FluentMigrator.Builder.Create.Index
Assembly: FluentMigrator.Extensions.Postgres.dll
Syntax
public interface ICreateBTreeIndexOptionsSyntax : ICreateIndexMethodOptionsSyntax, ICreateIndexOptionsSyntaxMethods
Fillfactor(int)
The fillfactor for an index is a percentage that determines how full the index method will try to pack index pages.
Declaration
ICreateBTreeIndexOptionsSyntax Fillfactor(int fillfactor)Parameters
| Type | Name | Description |
|---|---|---|
| int | fillfactor | The fillfactor value from 10 to 100 can be selected |
Returns
| Type | Description |
|---|---|
| ICreateBTreeIndexOptionsSyntax | The next step |
Remarks
For B-trees, leaf pages are filled to this percentage during initial index build, and also when extending the index at the right (adding new largest key values). If pages subsequently become completely full, they will be split, leading to gradual degradation in the index's efficiency. B-trees use a default fillfactor of 90, but any integer value from 10 to 100 can be selected. If the table is static then fillfactor 100 is best to minimize the index's physical size, but for heavily updated tables a smaller fillfactor is better to minimize the need for page splits. The other index methods use fillfactor in different but roughly analogous ways; the default fillfactor varies between methods.
VacuumCleanupIndexScaleFactor(float)
Specifies the fraction of the total number of heap tuples counted in the previous statistics collection that can be inserted without incurring an index scan at the VACUUM cleanup stage. This setting currently applies to B-tree indexes only. For more information about it see: https://www.postgresql.org/docs/current/runtime-config-client.html#GUC-VACUUM-CLEANUP-INDEX-SCALE-FACTOR
Declaration
ICreateBTreeIndexOptionsSyntax VacuumCleanupIndexScaleFactor(float point)Parameters
| Type | Name | Description |
|---|---|---|
| float | point | The value can range from 0 to 10000000000. When vacuum_cleanup_index_scale_factor is set to 0, index scans are never skipped during VACUUM cleanup. The default value is 0.1 |
Returns
| Type | Description |
|---|---|
| ICreateBTreeIndexOptionsSyntax | The next step |