[tor-commits] [metrics-web/master] Avoid SELECT MAX() on partitioned statusentry table.

[karsten at torproject.org]

commit 1400d7b99cd3e7ee32a58e0025ba2a56a16aa561
Author: Karsten Loesing <karsten.loesing at gmx.net>
Date:   Sat Jan 14 12:04:36 2012 +0100

    Avoid SELECT MAX() on partitioned statusentry table.
    
    For some reason, SELECT MAX() performs a full table scan on all child
    tables of a partitioned table.  Good thing we have a non-partitioned table
    containing the consensuses that has the same information.
---
 .../torproject/ernie/web/RouterDetailServlet.java  |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/src/org/torproject/ernie/web/RouterDetailServlet.java b/src/org/torproject/ernie/web/RouterDetailServlet.java
index 033e9e6..677c293 100644
--- a/src/org/torproject/ernie/web/RouterDetailServlet.java
+++ b/src/org/torproject/ernie/web/RouterDetailServlet.java
@@ -71,7 +71,7 @@ public class RouterDetailServlet extends HttpServlet {
         + "FROM statusentry JOIN descriptor "
         + "ON descriptor.descriptor = statusentry.descriptor "
         + "WHERE statusentry.validafter = "
-        + "(SELECT MAX(validafter) FROM statusentry) "
+        + "(SELECT MAX(validafter) FROM consensus) "
         + "AND statusentry.fingerprint = ?";
 
     try {