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Overview | Creating Segments | Attaching Segments |Querying Segments | Dropping Segments | Archiving Segments
Omnidex Segments are separated into types that describe their content and their format:
| Type | File Extensions | Description |
|---|---|---|
| INDEX | .odxid | This segment contains index pointers representing the rows that match the criteria. |
| DATA | .dat | This segment contains data in binary format without delimiters. |
| DELIMITED | .txt, .csv and .tdf | This segment contains data in character format, with one value per line. |
Omnidex Segments are separated into two types of persistence that describe how filenames and file cleanup are handled:
| Persistence | Description |
|---|---|
| TEMPORARY | Object names are unique to a connection, but may repeat across connections. Omnidex automatically manages the filenames for these segments. This segment can be dropped explicitly if needed; otherwise it will automatically dropped when the connection ends. Segments are temporary by default. |
| PERMANENT | Object names are unique to a connection, but may repeat across connections. The user must provide unique filenames for these segments; otherwise, the object name is used as the filename. This segment will only be deleted if explicitly dropped. |
Segments are easily creating using the CREATE SEGMENT statement. The following example shows a series of segments being created in a multi-step query.
> ; Create a series of index and data segment files, and then reuse them > ; in a final query. > > > ; Create a temporary index segment for Individuals in Denver, CO > create temporary index segment PART_1 >> as (select INDIVIDUALS.$UNIQUEKEY >> from INDIVIDUALS >> join HOUSEHOLDS on INDIVIDUALS.HOUSEHOLD = HOUSEHOLDS.HOUSEHOLD >> where STATE = 'CO' and >> CITY = 'Denver') >> with delete; Segment PART_1 created with 37 rows > ; Create a temporary index segment for Individuals in Phoenix, AZ; -> create temporary index segment PART_2 >> as (select INDIVIDUALS.$UNIQUEKEY >> from INDIVIDUALS >> join HOUSEHOLDS on INDIVIDUALS.HOUSEHOLD = HOUSEHOLDS.HOUSEHOLD >> where STATE = 'AZ' and >> CITY = 'Phoenix') >> with delete; Segment PART_2 created with 27 rows > ; Create a temporary index segment for Individuals born since 1980; > create temporary index segment PART_3 >> as (select INDIVIDUALS.$UNIQUEKEY >> from INDIVIDUALS >> where BIRTHDATE >= 'January 1, 1980') >> with delete; Segment PART_3 created with 1,882 rows
See also: