Administration: Omnidex Indexing

Index Creation

Declaring Indexes

The easiest way to add Omnidex indexes to a table is to append indexing information at the end of each column in the CREATE TABLE statement. This will suffice for most basic installations of Omnidex. The example below shows adding indexes to a table. Some columns have “omnidex” next to them, indicating that a standard Omnidex index should be created. Other columns have “quicktext” next to them, indicating that QuickText index should be created.

> create table          "HOUSEHOLDS"
>>  physical             "dat/households.dat"
>>  (
>>   "HOUSEHOLD"         CHARACTER(12)     omnidex,
>>   "ADDRESS"           CHARACTER(50)     quicktext,
>>   "CITY"              CHARACTER(28)     quicktext,
>>   "STATE"             CHARACTER(2)      omnidex,
>>   "ZIP"               CHARACTER(5)      omnidex,
>>   "COUNTRY"           CHARACTER(2)      omnidex,
>>   constraint HOUSEHOLDS_HOUSEHOLD_PK primary ("HOUSEHOLD")
>>  )
>>  in                   "simple.xml";
Table HOUSEHOLDS created in simple.xml
>

Some indexes require more options or more information. For example, a multi-column index - an index containing more than one column - cannot be created by simply putting a keyword next to a column. These indexes can be created one of two ways. The first, and most common way, is to declare them in the CREATE TABLE statement following all of the constraint declarations as shown in the example below.

> create table          "HOUSEHOLDS"
>>  physical             "dat/households.dat"
>>  (
>>   "HOUSEHOLD"         CHARACTER(12)     omnidex,
>>   "ADDRESS"           CHARACTER(50)     quicktext,
>>   "CITY"              CHARACTER(28)     quicktext,
>>   "STATE"             CHARACTER(2)      omnidex,
>>   "ZIP"               CHARACTER(5)      omnidex,
>>   "COUNTRY"           CHARACTER(2)      omnidex,
>>   constraint HOUSEHOLDS_HOUSEHOLD_PK primary ("HOUSEHOLD"),
>>   omnidex    STATE_CITY_ZIP ("STATE", "CITY", "ZIP") case_insensitive
>>  )
>>  in                   "simple.xml";
Table HOUSEHOLDS created in simple.xml
>

Omnidex indexes can also be created using CREATE INDEX statement. This is a more traditional approach; however, most administrators prefer to use the CREATE TABLE statement since it is easier to differentiate which columns are indexed and which are not. In either case, these statements only declare the indexes, but do not populate the indexes.

> create omnidex index  "STATE_CITY_ZIP"
>>  on                   "HOUSEHOLDS"
>>  (
>>    "STATE",
>>    "CITY", 
>>    "ZIP"
>>  )
>>  in                   "simple.xml";
Index STATE_CITY_ZIP created in simple.xml
>

Additional Resources

See also:

 
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admin/indexing/creation/declaring.txt · Last modified: 2016/06/28 22:38 (external edit)