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admin:indexing:indexes:groups [2011/01/21 00:50]
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admin:indexing:indexes:groups [2016/06/28 22:38] (current)
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 ==== Index Groups ==== ==== Index Groups ====
  
-Index Groups are used to combine multiple indexes into one single index. ​ This allows a search against any one index within the group to automatically search all indexes within the group. ​ For example, if a table has three lines, ADDRESS_LINE_1,​ ADDRESS_LINE_2 and ADDRESS_LINE_3,​ they can be indexed as an Index Group. ​ Criteria against any one of those three columns will automatically search all address lines.+Index Groups are used to combine multiple indexes into one single index. ​ This allows a search against any one index within the group to automatically search all indexes within the group. ​ For example, if a table has three lines, ADDRESS_LINE_1,​ ADDRESS_LINE_2and ADDRESS_LINE_3,​ they can be indexed as an Index Group. ​ Criteria against any one of those three columns will automatically search all address lines.
  
 In the example below, a row displays an address: In the example below, a row displays an address:
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 If these three columns are added to an Index Group, then the following search will locate the row: If these three columns are added to an Index Group, then the following search will locate the row:
  
 +<​code>​
   select ​       NAME, ADDRESS_LINE_1,​ ADDRESS_LINE_2,​ ADDRESS_LINE_3   select ​       NAME, ADDRESS_LINE_1,​ ADDRESS_LINE_2,​ ADDRESS_LINE_3
     from        CUSTOMERS     from        CUSTOMERS
     where       ​ADDRESS_LINE_1 = '1254 Broadway, Yonkers, NY'     where       ​ADDRESS_LINE_1 = '1254 Broadway, Yonkers, NY'
 +</​code>​
  
 Care should be taken when considering where to use Index Groups. ​ When indexes are combined into an Index Group, they lose the ability to distinguish which column originally contained the values. ​ This can lead to confusion. ​ For example, the following search will also locate the row: Care should be taken when considering where to use Index Groups. ​ When indexes are combined into an Index Group, they lose the ability to distinguish which column originally contained the values. ​ This can lead to confusion. ​ For example, the following search will also locate the row:
  
 +<​code>​
   select ​       NAME, ADDRESS_LINE_1,​ ADDRESS_LINE_2,​ ADDRESS_LINE_3   select ​       NAME, ADDRESS_LINE_1,​ ADDRESS_LINE_2,​ ADDRESS_LINE_3
     from        CUSTOMERS     from        CUSTOMERS
     where       ​ADDRESS_LINE_1 = '10710 Yonkers Street Suite 100'     where       ​ADDRESS_LINE_1 = '10710 Yonkers Street Suite 100'
 +</​code>​
  
 === Common Uses of Index Groups === === Common Uses of Index Groups ===
  
-Index Groups can be used in many different situations. ​ Here is a little of common situation where Index Groups are used:+Index Groups can be used in many different situations. ​ Here is a common situation where Index Groups are used:
  
   * Combining indexes for multiple address lines   * Combining indexes for multiple address lines
   * Combining indexes for a short-description column and a long-description column.   * Combining indexes for a short-description column and a long-description column.
-  * Combining indexes for given names, nicknames and aliases+  * Combining indexes for given names, nicknamesand aliases
   * Combining indexes for multiple telephone numbers   * Combining indexes for multiple telephone numbers
   * Combining indexes for multiple email addresses   * Combining indexes for multiple email addresses
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 If HOUSEHOLDS.HOME_PHONE and INDIVIDUALS.MOBILE_PHONE were added to an Index Group, then this household would be returned in the following query. ​ Note that the query searches the indexes in the INDIVIDUALS table **even though the INDIVIDUALS table is not referenced in the query.**  ​ If HOUSEHOLDS.HOME_PHONE and INDIVIDUALS.MOBILE_PHONE were added to an Index Group, then this household would be returned in the following query. ​ Note that the query searches the indexes in the INDIVIDUALS table **even though the INDIVIDUALS table is not referenced in the query.**  ​
  
 +<​code>​
   select ​       HOUSEHOLD, ADDRESS, CITY, STATE, ZIP   select ​       HOUSEHOLD, ADDRESS, CITY, STATE, ZIP
     from        HOUSEHOLDS     from        HOUSEHOLDS
     where       ​HOME_PHONE = '720 298 3162'     where       ​HOME_PHONE = '720 298 3162'
 +</​code>​
  
-As discussed above, care should be taken when considering where to use Index Groups across tables. ​ It can be confusing ​that when a table is searched without it being included ​in the SQL statement. ​ A row can also be qualified when a portion of the criteria exists in the parent and another portion exists in a child row.  For example, the following search will also locate this household:+As discussed above, care should be taken when considering where to use Index Groups across tables. ​ It can be confusing when a table is actually ​searched without it being referenced ​in the SQL statement. ​ A row can also be qualified when a portion of the criteria exists in the parent and another portion exists in a child row.  For example, the following search will also locate this household:
  
 +<​code>​
   select ​       HOUSEHOLD, ADDRESS, CITY, STATE, ZIP   select ​       HOUSEHOLD, ADDRESS, CITY, STATE, ZIP
     from        HOUSEHOLDS     from        HOUSEHOLDS
     where       ​HOME_PHONE = '303 298 2238'     where       ​HOME_PHONE = '303 298 2238'
 +</​code>​
  
 Because of this characteristic,​ Index Groups are best suited for a) Omnidex Indexes, b)  QuickText Indexes containing free-form text where the location of keywords is not material, or c) combinations of indexes where the data between columns is so different it would not be confused. Because of this characteristic,​ Index Groups are best suited for a) Omnidex Indexes, b)  QuickText Indexes containing free-form text where the location of keywords is not material, or c) combinations of indexes where the data between columns is so different it would not be confused.
 
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