A comparison of WD and TEXT indexes in terms of syntax and capability.
Feature |
Supported by WD index? |
Supported by TEXT index? |
|---|---|---|
Conjunction of terms |
Yes, expressed in the form:
tbl.col
CONTAINS('great','white'
,'whale')
|
Yes, expressed in the form:
CONTAINS(tbl.col,'great white whale') |
General boolean expressions |
Yes, expressed in the form:
tbl.col CONTAINS
('great') AND ( tbl.col
CONTAINS('white) OR
tbl.col CONTAINS('whale')
AND NOT tbl.col
CONTAINS('ship'))
|
Yes, expressed in the form:
CONTAINS(tbl.col, 'great AND ( white OR whale AND NOT ship )') |
Search for terms matching prefix |
No |
Yes, for example:
CONTAINS (tbl.col,'whale*') |
Acceleration of LIKE predicates |
Yes, for example:
tbl.col LIKE 'whale%' |
No |
Searches for terms in proximity |
No |
Yes, for example:
CONTAINS(tbl.col, 'white BEFORE whale') CONTAINS(tbl.col, 'whale NEAR white') CONTAINS(tbl.col, ' "white whale" ') |
Ordering of results based on search scoring |
No |
Yes |
In TEXT index, searching for terms matching a prefix and searching for a LIKE expression have different semantics and may return very different results depending on the text configuration. The specification of minimum length, maximum length and a stoplist will govern the prefix processing but does not affect LIKE semantics.