Web Staff Client: Number of search results on patron search

[Terran McCanna]

It would be useful to see the number of search results for any given search in the web client, particularly in the patron search interface.

[Galen Charlton (gmc)]

Agreed that it would be useful.

A number of data providers to egGrid don't currently report on the total result set size. For example, the patron search API accepts a limit and offset and returns a set of records, but the underlying database query doesn't return the total number of hits. It would be possible to have it first count, then return the records in the selected window, but the usability improvement from doing that would have to be balanced against the cost of the additional database query.

[Mike Rylander (mrylander)]

Just as a potential implementation note, it's possible to use a CTE for the main search and then select from the CTE twice, once to get the "window" of results based on limit/offset, and a second time to get the count. I used this technique in the "eliminate staged search" branch, and it works well. It's not free, but cost effective because non-recursive CTEs are only executed once in a query plan.

https://www.postgresql.org/docs/current/static/queries-with.html (search down for "a useful property")