Author: kwright
Date: Thu Sep 11 12:40:57 2014
New Revision: 1624270
URL: http://svn.apache.org/r1624270
Log:
Change PostgreSQL query conjunction clause generation behavior to work better
with 9.x
Modified:
manifoldcf/branches/CONNECTORS-1027/framework/core/src/main/java/org/apache/manifoldcf/core/database/DBInterfacePostgreSQL.java
Modified:
manifoldcf/branches/CONNECTORS-1027/framework/core/src/main/java/org/apache/manifoldcf/core/database/DBInterfacePostgreSQL.java
URL:
http://svn.apache.org/viewvc/manifoldcf/branches/CONNECTORS-1027/framework/core/src/main/java/org/apache/manifoldcf/core/database/DBInterfacePostgreSQL.java?rev=1624270&r1=1624269&r2=1624270&view=diff
==============================================================================
---
manifoldcf/branches/CONNECTORS-1027/framework/core/src/main/java/org/apache/manifoldcf/core/database/DBInterfacePostgreSQL.java
(original)
+++
manifoldcf/branches/CONNECTORS-1027/framework/core/src/main/java/org/apache/manifoldcf/core/database/DBInterfacePostgreSQL.java
Thu Sep 11 12:40:57 2014
@@ -1059,6 +1059,66 @@ public class DBInterfacePostgreSQL exten
return 25;
}
+ /* Calculate the number of values a particular clause can have, given the
values for all the other clauses.
+ * For example, if in the expression x AND y AND z, x has 2 values and z has
1, find out how many values x can legally have
+ * when using the buildConjunctionClause() method below.
+ */
+ @Override
+ public int findConjunctionClauseMax(ClauseDescription[]
otherClauseDescriptions)
+ {
+ // This implementation uses "OR"
+ return getMaxOrClause();
+ }
+
+ /* Construct a conjunction clause, e.g. x AND y AND z, where there is
expected to be an index (x,y,z,...), and where x, y, or z
+ * can have multiple distinct values, The proper implementation of this
method differs from database to database, because some databases
+ * only permit index operations when there are OR's between clauses, such as
x1 AND y1 AND z1 OR x2 AND y2 AND z2 ..., where others
+ * only recognize index operations when there are lists specified for each,
such as x IN (x1,x2) AND y IN (y1,y2) AND z IN (z1,z2).
+ */
+ @Override
+ public String buildConjunctionClause(List outputParameters,
ClauseDescription[] clauseDescriptions)
+ {
+ // This implementation uses "OR" instead of "IN ()" for multiple values,
since this generates better plans in Postgresql 9.x.
+ StringBuilder sb = new StringBuilder();
+ for (int i = 0 ; i < clauseDescriptions.length ; i++)
+ {
+ ClauseDescription cd = clauseDescriptions[i];
+ if (i > 0)
+ sb.append(" AND ");
+ String columnName = cd.getColumnName();
+ List values = cd.getValues();
+ String operation = cd.getOperation();
+ String joinColumn = cd.getJoinColumnName();
+ if (values != null)
+ {
+ if (values.size() > 1)
+ {
+ sb.append(" (");
+ for (int j = 0 ; j < values.size() ; j++)
+ {
+ if (j > 0)
+ sb.append(" OR ");
+ sb.append(columnName).append(operation).append("?");
+ outputParameters.add(values.get(j));
+ }
+ sb.append(")");
+ }
+ else
+ {
+ sb.append(columnName).append(operation).append("?");
+ outputParameters.add(values.get(0));
+ }
+ }
+ else if (joinColumn != null)
+ {
+ sb.append(columnName).append(operation).append(joinColumn);
+ }
+ else
+ sb.append(columnName).append(operation);
+ }
+ return sb.toString();
+ }
+
/** For windowed report queries, e.g. maxActivity or maxBandwidth, obtain
the maximum number of rows
* that can reasonably be expected to complete in an acceptable time.
*@return the maximum number of rows.
