From a4cbfdbe02af5a9842d35e7bfebd0a9fa566e44f Mon Sep 17 00:00:00 2001
From: Johannes Mey <johannes.mey@tu-dresden.de>
Date: Thu, 7 Feb 2019 15:10:26 +0100
Subject: [PATCH] keep index if no lookups AND no inserts occur. @kissinger is
this a good idea?
---
.../st/mquat/eris/coupling/ERISConnector.java | 19 +++++++++++++------
1 file changed, 13 insertions(+), 6 deletions(-)
diff --git a/jastadd-mquat-eris/src/main/java/de/tudresden/inf/st/mquat/eris/coupling/ERISConnector.java b/jastadd-mquat-eris/src/main/java/de/tudresden/inf/st/mquat/eris/coupling/ERISConnector.java
index e695c8a..06b53fd 100644
--- a/jastadd-mquat-eris/src/main/java/de/tudresden/inf/st/mquat/eris/coupling/ERISConnector.java
+++ b/jastadd-mquat-eris/src/main/java/de/tudresden/inf/st/mquat/eris/coupling/ERISConnector.java
@@ -273,14 +273,14 @@ public class ERISConnector {
// get the new config
ERISLPConfiguration newDOrOConfig = currentDOrIConfigs.get(attribute);
- ERISAttributeStatistics as = livingPartition.getAttributeStatistics(attribute);
+ ERISAttributeStatistics attributeStatistics = livingPartition.getAttributeStatistics(attribute);
logger.debug(" attribute {}:", attribute.getName());
logger.debug(" stats: lookups: {} inserts: {} scans: {} links: {} count: {}",
- as.getLookups(),
- as.getInserts(),
- as.getScans(),
- as.getLinks(),
- as.getCount());
+ attributeStatistics.getLookups(),
+ attributeStatistics.getInserts(),
+ attributeStatistics.getScans(),
+ attributeStatistics.getLinks(),
+ attributeStatistics.getCount());
// get the old config for the same attribute (if there is one)
Optional<ERISLPConfiguration> oldConfig = livingPartition.getConfigForAttribute(attribute, false);
@@ -342,6 +342,13 @@ public class ERISConnector {
} else {
logger.debug(" do NOT create an index {} to get an (index-) objective of {} (compared to {} without an index)", newIndexConfig, indexScore, lookupScoreWithoutIndex);
}
+ } else {
+ // TODO this is our guess, but it seems reasonable to not get rid of an index if it causes no harm
+ // if there are no inserts, keep a potentially existing index
+ if (attributeStatistics.getInserts() == 0) {
+ // see if there is an index for the current attribute
+ livingPartition.getConfigForAttribute(attribute, true).ifPresent(configsToUse::add);
+ }
}
}
}
--
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