[HBASE-1002] Coprocessors: Support small query language as filter on server side

• Type: Sub-task
• Status: Closed
• Priority: Minor
• Resolution: Duplicate
• Component/s: Filters
• Assignee: Unassigned
• Reporter: Andrew Kyle Purtell
• Created: 17/Nov/08 19:20
• Updated: 11/Jun/22 20:25
• Resolved: 13/Dec/10 23:58

Description

Improve the usability of filters by making them specifiable or executable using a little query language.

For example:

col("entry:price") > 3 && (col("entry:name") = "ABC" || col("entry:name") = "XYZ")

Can be implemented as a little language compiler that takes filter specifications as input and builds the requisite hierarchy of filter API classes and actions as emitted java code.

Compiler can be a utility class, something like:

Scan scan = new Scan();
scan.addFamily(Bytes.toBytes("entry"));
// ...
scan.setFilter(Filter.compile("col(\"entry:price\") > 3 && 
(col(\"entry:name\") =  \"ABC\" || col(\"entry:name\") = \"XYZ\""));
// ...

or even something like

Scan scan = Filter.compileScan("col(\"entry:price\") > 3 && 
(col(\"entry:name\") =  \"ABC\" || col(\"entry:name\") = \"XYZ\""));
// ...

Can also be implemented using JRuby snippets sent to the regionserver for execution, but this has troublesome security implications.

Issue Links

• is related to: HBASE-2396 Coprocessors: Server side dynamic scripting language execution
• is related to: HBASE-1696 [stargate] support specification of filters for scanners