[Glass] Indexes when objects have collection instance variables

[Dale K. Henrichs]

Hello Tim,

Well it turns out that you are using an index feature (using `*` as a path term; set valued path terms) that is not supported in the current 64bit products. It is a supported feature in the 32 bit product and is planned for re-introduction in 3.2.

In the absense of set-valued path terms, I think you have to think in terms of doing a little restructuring of your data structures ... possibly consolidating the startStopTimes collections into a single collection that can be indexed on the startingTimeStamp ... presumably you'd then need a reference back to the parent workorder (a primary predicate against a workorder id and secondary predicate against the startingTimestamp might do the trick) ...

Dale

----- Original Message -----
| From: "Tim Krieg" <tim.krieg at fargoAgile.com>
| To: glass at lists.gemtalksystems.com
| Sent: Tuesday, November 19, 2013 7:48:42 AM
| Subject: [Glass] Indexes when objects have collection instance variables
| 
| 
| 
| Hello,
| My name it Tim Krieg, and I'm a first time poster.
| 
| I have a question about creating an equalityIndex on an IdentitySet
| of
| objects that also contain another collection in one of its instance
| variables.
| 
| My application example is this:
| 
| A WorkOrder list returns a collection of WorkOrders.  A WorkOrder has
| an
| instance variable called startStopTimes (anOrderedCollection) and
| that
| returns a collection of TPTimeStampRange objects that keeps track of
| the
| startingTimeStamp and endingTimeStamp along with its duration.
| 
| Because a workOrder can be started and stopped multiple times, it's
| very
| common that the WorkOrder>>startStopTimes collection returns multiple
| instances, but I'd like the UI to support fast WorkOrder queries by
| the
| earliest startTimeStamp and the latest stopTimeStamp as well.
| 
| I'm not sure of the syntax when creating an equalityIndex on the
| startingTimeStamp and endingTimeStamp variables starting with the
| WorkOrder
| objects.
| 
| I've seen examples in the manual for the select path that goes
| something
| like this:
| select: { :wo | wo.startStopTimes.*.startingTimeStamp >= aTimestamp
| }.
| 
| How would you create an index on this WorkOrder class>>list
| IdentitySet to
| speed up this query?
| 
| WorkOrder list
|         createEqualityIndexOn: 'startStopTimes.*.startingTimeStamp'
|         withLastElementClass: TimeStamp.
| 
| I tried the above (along with a few variations), but obviously it
| didn't
| work.  I could also use advice on the select for retrieving the
| earliest
| startTimestamp and latest endingTimeStamp as well.  I have it working
| using
| the usual select: method with Smalltalk syntax, but not with Gemstone
| indexed path syntax as I need the query to be fast.
| 
| Thanks in advance,
| Tim
| 
| 
| 
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| http://forum.world.st/Indexes-when-objects-have-collection-instance-variables-tp4723419.html
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