private static Pair<IndexMultiKey, EventTableAndNamePair> FindIndex(
ISet<string> keyNamesAvailable,
ISet<string> rangeNamesAvailable,
EventTableIndexRepository indexRepository,
VirtualDWView virtualDataWindow,
Attribute[] annotations)
{
if (virtualDataWindow != null) {
var tablePairNoName = VirtualDWQueryPlanUtil.GetFireAndForgetDesc(
virtualDataWindow.EventType,
keyNamesAvailable,
rangeNamesAvailable);
return new Pair<IndexMultiKey, EventTableAndNamePair>(
tablePairNoName.First,
new EventTableAndNamePair(tablePairNoName.Second, null));
}
var indexHint = IndexHint.GetIndexHint(annotations);
IList<IndexHintInstruction> optionalIndexHintInstructions =
indexHint != null ? indexHint.GetInstructionsFireAndForget() : null;
return indexRepository.FindTable(keyNamesAvailable, rangeNamesAvailable, optionalIndexHintInstructions);
}
public static ICollection<EventBean> Snapshot(
QueryGraph filterQueryGraph,
Attribute[] annotations,
VirtualDWView virtualDataWindow,
EventTableIndexRepository indexRepository,
string objectName,
AgentInstanceContext agentInstanceContext)
{
var queryGraphValue = filterQueryGraph == null
? null
: filterQueryGraph.GetGraphValue(QueryGraphForge.SELF_STREAM, 0);
if (queryGraphValue == null || queryGraphValue.Items.IsEmpty()) {
if (virtualDataWindow != null) {
Pair<IndexMultiKey, EventTable> pair = VirtualDWQueryPlanUtil.GetFireAndForgetDesc(
virtualDataWindow.EventType,
new EmptySet<string>(),
new EmptySet<string>());
return virtualDataWindow.GetFireAndForgetData(
pair.Second,
CollectionUtil.OBJECTARRAY_EMPTY,
new RangeIndexLookupValue[0],
annotations);
}
return null;
}
// determine custom index
var customResult = SnapshotCustomIndex(
queryGraphValue,
indexRepository,
annotations,
agentInstanceContext,
objectName);
if (customResult != null) {
return customResult.Value;
}
// determine lookup based on hash-keys and ranges
var keysAvailable = queryGraphValue.HashKeyProps;
ISet<string> keyNamesAvailable = keysAvailable.Indexed.Length == 0
? (ISet<string>) new EmptySet<string>()
: (ISet<string>) new HashSet<string>(keysAvailable.Indexed);
var rangesAvailable = queryGraphValue.RangeProps;
ISet<string> rangeNamesAvailable = rangesAvailable.Indexed.Length == 0
? (ISet<string>) new EmptySet<string>()
: (ISet<string>) new HashSet<string>(rangesAvailable.Indexed);
Pair<IndexMultiKey, EventTableAndNamePair> tablePair;
// find index that matches the needs
tablePair = FindIndex(
keyNamesAvailable,
rangeNamesAvailable,
indexRepository,
virtualDataWindow,
annotations);
// regular index lookup
if (tablePair != null) {
return SnapshotIndex(
keysAvailable,
rangesAvailable,
tablePair,
virtualDataWindow,
annotations,
agentInstanceContext,
objectName);
}
// in-keyword lookup
var inkwResult = SnapshotInKeyword(
queryGraphValue,
indexRepository,
virtualDataWindow,
annotations,
agentInstanceContext,
objectName);
if (inkwResult != null) {
return inkwResult.Value;
}
QueryPlanReportTableScan(annotations, agentInstanceContext, objectName);
return null;
}