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admin:features:segments:index [2012/03/06 21:49] doc |
admin:features:segments:index [2016/06/28 22:38] (current) |
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| [[admin:features:segments:home|Overview]] | | [[admin:features:segments:home|Overview]] | | ||
| **[[admin:features:segments:index|Index Segments]]** | | **[[admin:features:segments:index|Index Segments]]** | | ||
| + | [[admin:features:segments:data|Data Segments]] | | ||
| [[admin:features:segments:creating|Creating Segments]] | | [[admin:features:segments:creating|Creating Segments]] | | ||
| [[admin:features:segments:querying|Querying Segments]] | | [[admin:features:segments:querying|Querying Segments]] | | ||
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| ==== Index Segments ==== | ==== Index Segments ==== | ||
| + | === Overview === | ||
| Some applications process their queries in multiple steps. The first step isolates some rows based on a first group of criteria. The second step either refines those rows, or isolates a new set of rows based on a second group of criteria. At the end of the query, all of the steps are combined to produce a final result set. | Some applications process their queries in multiple steps. The first step isolates some rows based on a first group of criteria. The second step either refines those rows, or isolates a new set of rows based on a second group of criteria. At the end of the query, all of the steps are combined to produce a final result set. | ||
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| <code> | <code> | ||
| - | > ; Create a segment for Individuals in Denver, CO | + | > ; Create an index segment for Individuals in Denver, CO |
| - | > create segment PART_1 | + | > create index segment PART_1 |
| >> as (select INDIVIDUALS.$UNIQUEKEY | >> as (select INDIVIDUALS.$UNIQUEKEY | ||
| >> from INDIVIDUALS | >> from INDIVIDUALS | ||
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| Segment PART_1 created with 37 rows | Segment PART_1 created with 37 rows | ||
| - | > ; Create segment for Individuals in Phoenix, AZ; | + | > ; Create an index segment for Individuals in Phoenix, AZ; |
| - | -> create segment PART_2 | + | -> create index segment PART_2 |
| >> as (select INDIVIDUALS.$UNIQUEKEY | >> as (select INDIVIDUALS.$UNIQUEKEY | ||
| >> from INDIVIDUALS | >> from INDIVIDUALS | ||
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| Segment PART_2 created with 27 rows | Segment PART_2 created with 27 rows | ||
| - | > ; Create segment for Individuals born since 1990; | + | > ; Create an index segment for Individuals born since 1990; |
| - | > create segment PART_3 | + | > create index segment PART_3 |
| >> as (select INDIVIDUALS.$UNIQUEKEY | >> as (select INDIVIDUALS.$UNIQUEKEY | ||
| >> from INDIVIDUALS | >> from INDIVIDUALS | ||
| Line 53: | Line 55: | ||
| </code> | </code> | ||
| - | === Querying Index Segments === | + | === Using Index Segments in Queries === |
| Omnidex Segments can be referenced as criteria in a future query using the [[dev:sql:functions:segment:home|$SEGMENT]] function. The $SEGMENT function references the object name for any segment previously created in the same connection. Since Omnidex Segments already contain index pointers, they are incorporated into a search with very high performance. | Omnidex Segments can be referenced as criteria in a future query using the [[dev:sql:functions:segment:home|$SEGMENT]] function. The $SEGMENT function references the object name for any segment previously created in the same connection. Since Omnidex Segments already contain index pointers, they are incorporated into a search with very high performance. | ||
| - | The following example shows several segments that were created in the previous page being referenced in a query using the $SEGMENT function: | + | The following example shows several segments that were above being referenced in a query using the $SEGMENT function: |
| <code> | <code> | ||