Tom Lane <[EMAIL PROTECTED]> writes: > No, what you'll get is something like > > int4var::float8 float8eq float8var > > which is perfectly mergejoinable ... however, it's not clear that the > planner will make very good estimates about the value of the cast > expression. I'm not sure if it's worth introducing a pile more > crosstype operators to change that situation --- improving > the selectivity functions to handle casts better might be a wiser > approach.
So the only reason we needed the cross-data-type operators was to get better estimates? I thought without them you couldn't get an index-based plan at all. -- Gregory Stark EnterpriseDB http://www.enterprisedb.com ---------------------------(end of broadcast)--------------------------- TIP 9: In versions below 8.0, the planner will ignore your desire to choose an index scan if your joining column's datatypes do not match
