[TAP] case sensitivity of query -- content

[Patrick Dowler]

* summary of where we are with respect to case sensitive (or not) evaluation 
of comparisons with character data in columns:

- ADQL (SQL) is clearly case sensitive with respect to comparison operators

- normally the query writer makes comparisons case insensitive by using string 
manipulation function (lower, upper); these function names are reserved words 
in ADQL 2.0 but they are not defined in the BNF

- some DBs have options/settings to make operators like = case insensitive

- some (many?) DBs allow for the creation of indices on function return 
values, so that something like  lower(col1) = 'foo' can be optimised via 
indexed access

- TAP could be used with other query languages with different rules w.r.t. 
case sensitivity of comparison operators

Is this an issue for TAP or is it strictly within the realm of the query 
language to specify this behaviour?


-- 

Patrick Dowler
Tel/Tél: (250) 363-0044
Canadian Astronomy Data Centre
National Research Council Canada
5071 West Saanich Road
Victoria, BC V9E 2M7

Centre canadien de donnees astronomiques
Conseil national de recherches Canada
5071, chemin West Saanich
Victoria (C.-B.) V9E 2M7