weighted_sum

The weighted_sum UDAF takes a weight, type, and type-weight mapping to produce an aggregated weight. For example, consider the following SQL snippet:

   SELECT query,
          doc_id,
          filters,
          weighted_sum(typed_weight_d, type, 'click:1.0,cart:10.0') AS weight_d
     FROM signal_type_groups
 GROUP BY query, doc_id, filters

When applied to the rows in the table below, the weighted_sum function produces a final weight_d of 12.0 (2*1.0 + 1*10.0). The UDAF is passed rows grouped by query, doc_id, and filters.

query type doc_id filters typed_weight_d

`query`	`type`	`doc_id`	`filters`	`typed_weight_d`
`iPad`	`click`	`1`	`gear`	`2`
`iPad`	`cart`	`1`	`gear`	`1`

iPad

click

1

gear

2

iPad

cart

1

gear

1