Re: JDBC slow performance on resultSet iteration? - Mailing list pgsql-jdbc

Just an quick info update: i'm using the postgresql-9.2-1003-jdbc4 driver

On 2013/11/05, at 16:09, Rui Pedro Leal wrote:

> Hello everyone,
>
> I'm having slow JDBC performance on iterating a resultSet obtained from a somewhat simple query.
>
> The query, although using PostGIS functions, is pretty straight forward:
>
> SELECT _id, _spatial_type, ST_AsBinary(_geometry), _attribute, _count, _references, countpersons, countfatals,
countdrunks,density 
> FROM accidents_5
> WHERE (_geometry && ST_MakeEnvelope(-126.60644531250001,26.43122806450644,-63.369140625,52.96187505907603, 4326) )
> ORDER BY _pk_id
>
> The results are the following:
> - Executing the query directly from pgAdmin: ~2807ms
> - Executing from JVM + JDBC: 4184ms
>
> The code i'm executing is pretty much standard:
>
> -------------------- code --------------------
>
>     public static void main(final String[] args) throws Exception {
>
>         String sql = "SELECT _id, _spatial_type, ST_AsBinary(_geometry), _attribute, _count, _references,
countpersons,countfatals, countdrunks, density"; 
>         sql += " FROM accidents_5";
>         sql += " WHERE (_geometry &&
ST_MakeEnvelope(-126.60644531250001,26.43122806450644,-63.369140625,52.96187505907603,4326) )"; 
>         sql += " ORDER BY _pk_id";
>
>         System.out.println(sql);
>
>         Long time = System.currentTimeMillis();
>         try {
>             Connection connection = DataStoreInfo.getDataStores().get(0);
>             connection.setAutoCommit(false);
>
>             System.out.println("[QUERY " + Thread.currentThread().getId()
>                     + "] - connection in "
>                     + (System.currentTimeMillis() - time) + "ms.");
>
>             Statement st = connection.createStatement(
>                     ResultSet.TYPE_FORWARD_ONLY, ResultSet.CONCUR_READ_ONLY,
>                     ResultSet.CLOSE_CURSORS_AT_COMMIT);
>             st.setFetchSize(250);
>
>             System.out.println("[QUERY " + Thread.currentThread().getId()
>                     + "] - statement in " + (System.currentTimeMillis() - time)
>                     + "ms.");
>
>             ResultSet resultSet = st.executeQuery(sql);
>
>             System.out.println("[QUERY " + Thread.currentThread().getId()
>                     + "] - done in " + (System.currentTimeMillis() - time)
>                     + "ms.");
>
>             GeometryFactory geofact = new GeometryFactory(new PrecisionModel(),4326);
>             WKBReader wkbReader = new WKBReader(geofact);
>
>             String id;
>             String spatialType;
>             Geometry geometry;
>             String attribute;
>             Long count;
>             String reference;
>             Map<String, Double> properties;
>             String granularSynthString = "GranularSynthesis";
>
>             while (resultSet.next()) {
>                 id = resultSet.getString(1);
>                 spatialType = resultSet.getString(2);
>
>                 // geometry = wkbReader.read(resultSet.getBytes(3)); // ignored the WKBReader and the results are
aboutthe same. 
>                 attribute = resultSet.getString(4);
>                 count = resultSet.getLong(5);
>                 reference = resultSet.getString(6);
>
>                 properties = new HashMap<String, Double>();
>                 Double aux = resultSet.getDouble(7);
>                 properties.put("countpersons", aux);
>                 aux = resultSet.getDouble(8);
>                 properties.put("countfatals", aux);
>                 aux = resultSet.getDouble(9);
>                 properties.put("countdrunks", aux);
>                 aux = resultSet.getDouble(10);
>                 properties.put("density", aux);
>             }
>
>             System.out.println("[QUERY " + Thread.currentThread().getId()
>                     + "] - done & iterated in "
>                     + (System.currentTimeMillis() - time) + "ms.");
>
>             resultSet.close();
>             st.close();
>             connection.commit();
>             connection.close();
>         } catch (SQLException exception) {
>             exception.printStackTrace();
>         // } catch (ParseException exception) {  // ignored from WKBreader
>         // exception.printStackTrace();
>         }
>
>         System.out.println("[End " + Thread.currentThread().getId()
>                 + "] - done in " + (System.currentTimeMillis() - time) + "ms.");
>     }
>
> -------------------- end code --------------------
>
> Although i'm executing this on slow MacbookPro (2.6 core duo, 2Gbs RAM but SSD) and have a 9.1.2 postgres, i've also
testedthis on a recent retina MBP and the ratio between pgAdmin and JDBC execution is similar. 
>
> Is this expected? Can someone point if i'm doing something terrible wrong?
>
> I'm not concerned about the query performance per-se (i know it CAN be optimized), but the differences just using
JDBCand iterating the resultSet are really annoying. 
>
> Thanks in advance for any help.
>
> Kind regards,
>
> Rui Leal
>
>