Notes.DL

DALServer SVN Revision 21
Sep 29, 2015
=========================

vendor/cds-savot-4.0		+
    Added v4.0 of the SAVOT lib to the source tree.  This isn't used yet
    but can optmize things later thru use of ArrayList instead of Vector
    in the savot/model/SavotSet.java code.  Using this would require changes
    to dalserver$src/dalserver/tap/TapQueryResponse.java as well.  

    Source obtained by cloning https://github.com/aschaaff/savot

vendor/cds-savot-3.0/savot/model/SavotSet.java
    Changed the initialization in addItem() of the Vector object to be

            set = new Vector<Object>(1024, 32 * 1024);

    This is an optimization for large tables where we assume a row won't 
    have more than 1024 columns, and if we have to resize we do so at 32K
    row increments.  In testing a table with 500K rows, 89 of 92 seconds
    taken to write the VOTable was wasted in resizing the Vector as new
    table rows were added to the document, this change is a 20x improvement.

vendor/cds-savot-3.0/savot/pull/SavotPullEnginge.java
    Removed 16-bit char from comment on line 454.

src/dalserver/DbmsQuery.java
    Disabled autoCommit in the connect() method for Postgres so the fetch
    size works.  This is done explicitly in the TAP code, but not for SCS.

src/dalserver/scs/ScsQuery.java
    - Added an optional 'schemaName' parameter to allow the SCS to query
      a table in a named schema.  The schema is set in the SCS config file
      under the [init-params] section.
    - Added a 'maxrec' parameter so we can set this in the result table
      to enforce the size.  This wasn't working before and a better fix 
      may be required.
    - Set the DB fetch size and direction explicitly to optimize the query.

src/dalserver/tap/TapQueryRunner.java
    Increased size of setFetchSize() from 1000 to 10000.

src/dalserver/tap/TapTableWriter.java
    Added a 'maxrec' setting in the setJob() method to enforce size.