[CASSANDRA-1339] add support for GT, GTE index expressions

• Type: New Feature
• Status: Resolved
• Priority: Normal
• Resolution: Later
• Fix Version/s: 0.7.1
• Component/s: Legacy/CQL
• Assignee: Unassigned
• Reporter: Jonathan Ellis
• Created: 29/Jul/10 22:07
• Updated: 16/Apr/19 09:33
• Resolved: 11/Jan/11 17:15

Description

this will require hitting every node in the cluster and merging results, unlike with EQ.

For instance, say we have the following index rows for some hypothetical column C1:

Node 1, ('' - M]
4: A G K
5: B F J M

Node 2, (M - '']
4: N P X
5: Q R T

Because we store the index columns sorted in partitioner order, queries for C1=4 can scan first node 1, then if insufficient data is found, proceed to node 2. But for GT or GTE queries we have to scan everyone and merge. (Since we don't know what the next value after 4 is. So an alternative would be for each node to send back, along with the data for the first row, the row key that comes next. This would be very very messy.)

Note that since we don't yet support range scans backwards, we can't support LT or LTE queries. The easiest workaround there would be to add a way to specify that you want to create an index on the comparator, reversed. This is also worth doing for optimizations within normal columns – see CASSANDRA-1338.

Issue Links

• is blocked by: CASSANDRA-1472 Add bitmap secondary indexes