From f09618b63a3e842adc59360c9bb4cf0ad37246ef Mon Sep 17 00:00:00 2001
From: Eelco Dolstra <e.dolstra@tudelft.nl>
Date: Wed, 27 Oct 2004 10:24:44 +0000
Subject: [PATCH] * Turn on read-only mode in queries.  This prevents redundant
 store I/O.

---
 src/nix-env/main.cc | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/nix-env/main.cc b/src/nix-env/main.cc
index f87c413126..c25cdb60ca 100644
--- a/src/nix-env/main.cc
+++ b/src/nix-env/main.cc
@@ -516,6 +516,8 @@ static void opQuery(Globals & globals,
 
     enum { sInstalled, sAvailable } source = sInstalled;
 
+    readOnlyMode = true; /* makes evaluation a bit faster */
+
     for (Strings::iterator i = opFlags.begin();
          i != opFlags.end(); ++i)
         if (*i == "--status" || *i == "-s") printStatus = true;