Changes between Version 6 and Version 7 of OracleBranch

Timestamp:

May 3, 2007, 10:46:08 AM (18 years ago)

Author:

Matt Boersma

Comment:

Added Oracle limitations of TextFields

OracleBranch

@@ -79 +79 @@
 cx_Oracle always returns either datetime.datetime objects or its own Timestamp objects when fetching date or time-related fields.  The !OracleQuerySet.resolve_columns method is used to cast values from the database to the proper type for the Field.
 
-=== LOB manipulation ===
+=== !TextField limitations ===
 
-The oracle backend stores !TextFields as NCLOB columns, for which cx_Oracle requires some extra manipulation to fetch.  This is automatically handled by !OracleQuerySet.resolve_columns.
+The oracle backend stores !TextFields as NCLOB columns, for which cx_Oracle requires some extra manipulation to fetch. This is automatically handled by !OracleQuerySet.resolve_columns. Oracle also poses some limitations on the usage of LOB columns:
+
+  * LOB columns may not be used as primary keys.
+  * LOB columns may not be used in indexes.
+  * LOB columns may not be used in a "SELECT DISTINCT" list. This means that attempting to use the !QuerySet.distinct method on a model that includes !TextField columns will result in an error. A workaround to this is to keep !TextFields out of any models that you foresee performing .distinct queries on, and to include the !TextFields in a related model instead.
 
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