[sql] Import reference version of SQLite 3.17..

third_party/sqlite/sqlite-src-3170000/test/shrink.test

+# 2011 November 16
+#
+# The author disclaims copyright to this source code.  In place of
+# a legal notice, here is a blessing:
+#
+#    May you do good and not evil.
+#    May you find forgiveness for yourself and forgive others.
+#    May you share freely, never taking more than you give.
+#
+#***********************************************************************
+#
+# This file contains test cases for sqlite3_db_release_memory and
+# the PRAGMA shrink_memory statement.
+#
+
+set testdir [file dirname $argv0]
+source $testdir/tester.tcl
+test_set_config_pagecache 0 0
+
+unset -nocomplain baseline
+do_test shrink-1.1 {
+  db eval {
+    PRAGMA cache_size = 2000;
+    CREATE TABLE t1(x,y);
+    INSERT INTO t1 VALUES(randomblob(1000000),1);
+  }
+  set ::baseline sqlite3_memory_used
+  # EVIDENCE-OF: R-58814-63508 The sqlite3_db_release_memory(D) interface
+  # attempts to free as much heap memory as possible from database
+  # connection D.
+  sqlite3_db_release_memory db
+  expr {$::baseline > [sqlite3_memory_used]+500000}
+} {1}
+do_test shrink-1.2 {
+  set baseline [sqlite3_memory_used]
+  db eval {
+    UPDATE t1 SET y=y+1;
+  }
+  expr {$::baseline+500000 < [sqlite3_memory_used]}
+} {1}
+do_test shrink-1.3 {
+  set baseline [sqlite3_memory_used]
+  db eval {PRAGMA shrink_memory}
+  expr {$::baseline > [sqlite3_memory_used]+500000}
+} {1}
+
+test_restore_config_pagecache
+finish_test