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Posted to commits@cassandra.apache.org by sl...@apache.org on 2014/02/21 14:03:22 UTC
git commit: Disallow post-query re-ordering when paging
Repository: cassandra
Updated Branches:
refs/heads/cassandra-2.0 54a7e0034 -> 458965673
Disallow post-query re-ordering when paging
patch by slebresne; reviewed by iamaleksey for CASSANDRA-6722
Project: http://git-wip-us.apache.org/repos/asf/cassandra/repo
Commit: http://git-wip-us.apache.org/repos/asf/cassandra/commit/45896567
Tree: http://git-wip-us.apache.org/repos/asf/cassandra/tree/45896567
Diff: http://git-wip-us.apache.org/repos/asf/cassandra/diff/45896567
Branch: refs/heads/cassandra-2.0
Commit: 4589656733cab73776ec16cf485dee984718a7e3
Parents: 54a7e00
Author: Sylvain Lebresne <sy...@datastax.com>
Authored: Fri Feb 21 14:02:15 2014 +0100
Committer: Sylvain Lebresne <sy...@datastax.com>
Committed: Fri Feb 21 14:02:15 2014 +0100
----------------------------------------------------------------------
CHANGES.txt | 1 +
.../cql3/statements/SelectStatement.java | 69 ++++----------------
2 files changed, 14 insertions(+), 56 deletions(-)
----------------------------------------------------------------------
http://git-wip-us.apache.org/repos/asf/cassandra/blob/45896567/CHANGES.txt
----------------------------------------------------------------------
diff --git a/CHANGES.txt b/CHANGES.txt
index a5e1016..b25ff47 100644
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -20,6 +20,7 @@
* Fix replaying pre-2.0 commit logs (CASSANDRA-6714)
* Add static columns to CQL3 (CASSANDRA-6561)
* Optimize single partition batch statements (CASSANDRA-6737)
+ * Disallow post-query re-ordering when paging (CASSANDRA-6722)
Merged from 1.2:
* Catch memtable flush exceptions during shutdown (CASSANDRA-6735)
* Fix broken streams when replacing with same IP (CASSANDRA-6622)
http://git-wip-us.apache.org/repos/asf/cassandra/blob/45896567/src/java/org/apache/cassandra/cql3/statements/SelectStatement.java
----------------------------------------------------------------------
diff --git a/src/java/org/apache/cassandra/cql3/statements/SelectStatement.java b/src/java/org/apache/cassandra/cql3/statements/SelectStatement.java
index 2636c83..9fbed03 100644
--- a/src/java/org/apache/cassandra/cql3/statements/SelectStatement.java
+++ b/src/java/org/apache/cassandra/cql3/statements/SelectStatement.java
@@ -219,6 +219,11 @@ public class SelectStatement implements CQLStatement, MeasurableForPreparedCache
if (parameters.isCount)
return pageCountQuery(pager, variables, pageSize, now);
+ // We can't properly do post-query ordering if we page (see #6722)
+ if (needsPostQueryOrdering())
+ throw new InvalidRequestException("Cannot page queries with both ORDER BY and a IN restriction on the partition key; you must either remove the "
+ + "ORDER BY or the IN and sort client side, or disable paging for this query");
+
List<Row> page = pager.fetchPage(pageSize);
ResultMessage.Rows msg = processResults(page, variables, limit, now);
if (!pager.isExhausted())
@@ -931,56 +936,6 @@ public class SelectStatement implements CQLStatement, MeasurableForPreparedCache
return expressions;
}
- private Iterable<Column> columnsInOrder(final ColumnFamily cf, final List<ByteBuffer> variables) throws InvalidRequestException
- {
- if (columnRestrictions.length == 0)
- return cf.getSortedColumns();
-
- // If the restriction for the last column alias is an IN, respect
- // requested order
- Restriction last = columnRestrictions[columnRestrictions.length - 1];
- if (last == null || last.isSlice())
- return cf.getSortedColumns();
-
- ColumnNameBuilder builder = cfDef.getColumnNameBuilder();
- for (int i = 0; i < columnRestrictions.length - 1; i++)
- builder.add(columnRestrictions[i].values(variables).get(0));
-
-
- List<ByteBuffer> values = last.values(variables);
- final List<ByteBuffer> requested = new ArrayList<ByteBuffer>(values.size());
- Iterator<ByteBuffer> iter = values.iterator();
- while (iter.hasNext())
- {
- ByteBuffer t = iter.next();
- ColumnNameBuilder b = iter.hasNext() ? builder.copy() : builder;
- requested.add(b.add(t).build());
- }
-
- return new Iterable<Column>()
- {
- public Iterator<Column> iterator()
- {
- return new AbstractIterator<Column>()
- {
- // If the query is reversed, we'll reverse everything in the end, so return the
- // requested in reversed order so we do return values in requested order in the end
- Iterator<ByteBuffer> iter = (isReversed ? Lists.reverse(requested) : requested).iterator();
- public Column computeNext()
- {
- while (iter.hasNext())
- {
- Column column = cf.getColumn(iter.next());
- if (column != null)
- return column;
- }
- return endOfData();
- }
- };
- }
- };
- }
-
private ResultSet process(List<Row> rows, List<ByteBuffer> variables, int limit, long now) throws InvalidRequestException
{
Selection.ResultSetBuilder result = selection.resultSetBuilder(now);
@@ -1027,7 +982,7 @@ public class SelectStatement implements CQLStatement, MeasurableForPreparedCache
else if (cfDef.isCompact)
{
// One cqlRow per column
- for (Column c : columnsInOrder(cf, variables))
+ for (Column c : cf)
{
if (c.isMarkedForDelete(now))
continue;
@@ -1144,16 +1099,18 @@ public class SelectStatement implements CQLStatement, MeasurableForPreparedCache
return true;
}
+ private boolean needsPostQueryOrdering()
+ {
+ // We need post-query ordering only for queries with IN on the partition key and an ORDER BY.
+ return keyIsInRelation && !parameters.orderings.isEmpty();
+ }
+
/**
* Orders results when multiple keys are selected (using IN)
*/
private void orderResults(ResultSet cqlRows)
{
- // There is nothing to do if
- // a. there are no results,
- // b. no ordering information where given,
- // c. key restriction is a Range or not an IN expression
- if (cqlRows.size() == 0 || parameters.orderings.isEmpty() || isKeyRange || !keyIsInRelation)
+ if (cqlRows.size() == 0 || !needsPostQueryOrdering())
return;
assert orderingIndexes != null;