[jira] [Commented] (UIMA-2434) Feature structure removal from sorted index is very slow

["Richard Eckart de Castilho (JIRA)" <de...@uima.apache.org>]

    [ https://issues.apache.org/jira/browse/UIMA-2434?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13419772#comment-13419772 ] 

Richard Eckart de Castilho commented on UIMA-2434:
--------------------------------------------------

+1 for bulk removal. FSIterators don't like it when feature structures are removed from the CAS while iterating over it, so we usually collect all FS to remove in a list and bulk-remove them in the end.

                
> Feature structure removal from sorted index is very slow
> --------------------------------------------------------
>
>                 Key: UIMA-2434
>                 URL: https://issues.apache.org/jira/browse/UIMA-2434
>             Project: UIMA
>          Issue Type: Improvement
>          Components: Core Java Framework
>    Affects Versions: 2.3.1SDK
>            Reporter: Mikhail Sogrin
>
> Removal of feature structures from sorted indexes (e.g. default index) is very slow. FSIntArrayIndex.remove() method performs two operations: linear search in the array until the given FS is found, followed by the shift of elements to the end of this array by one position to the left.
> If many annotations (millions and more) are being deleted at once, this operation gets very very slow - much slower than adding these annotations in the first place. It seems to require O(N^2) time to remove N annotations.
> One item is the linear search, which can be replaced by the binary search method, which is already implemented in the same class.
> Second, array copy can be done with Java built-in method instead of a custom loop.
> Ideally, a method for bulk removal of a collection of annotations would have been the most efficient, for example a method to remove all annotations of a given type.

--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators: https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa
For more information on JIRA, see: http://www.atlassian.com/software/jira