Import SQLite 3.7.6.3.

third_party/sqlite/src/test/analyze4.test

+# 2011 January 04
+#
+# 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 implements regression tests for SQLite library. This file 
+# implements tests for ANALYZE to verify that multiple rows containing
+# a NULL value count as distinct rows for the purposes of analyze 
+# statistics.
+#
+# Also include test cases for collating sequences on indices.
+#
+
+set testdir [file dirname $argv0]
+source $testdir/tester.tcl
+
+do_test analyze4-1.0 {
+  db eval {
+    CREATE TABLE t1(a,b);
+    CREATE INDEX t1a ON t1(a);
+    CREATE INDEX t1b ON t1(b);
+    INSERT INTO t1 VALUES(1,NULL);
+    INSERT INTO t1 SELECT a+1, b FROM t1;
+    INSERT INTO t1 SELECT a+2, b FROM t1;
+    INSERT INTO t1 SELECT a+4, b FROM t1;
+    INSERT INTO t1 SELECT a+8, b FROM t1;
+    INSERT INTO t1 SELECT a+16, b FROM t1;
+    INSERT INTO t1 SELECT a+32, b FROM t1;
+    INSERT INTO t1 SELECT a+64, b FROM t1;
+    ANALYZE;
+  }
+
+  # Should choose the t1a index since it is more specific than t1b.
+  db eval {EXPLAIN QUERY PLAN SELECT * FROM t1 WHERE a=5 AND b IS NULL}
+} {0 0 0 {SEARCH TABLE t1 USING INDEX t1a (a=?) (~1 rows)}}
+
+# Verify that the t1b index shows that it does not narrow down the
+# search any at all.
+#
+do_test analyze4-1.1 {
+  db eval {
+    SELECT idx, stat FROM sqlite_stat1 WHERE tbl='t1' ORDER BY idx;
+  }
+} {t1a {128 1} t1b {128 128}}
+
+# Change half of the b values from NULL to a constant.  Verify
+# that the number of rows selected in stat1 is half the total 
+# number of rows.
+#
+do_test analyze4-1.2 {
+  db eval {
+    UPDATE t1 SET b='x' WHERE a%2;
+    ANALYZE;
+    SELECT idx, stat FROM sqlite_stat1 WHERE tbl='t1' ORDER BY idx;
+  }
+} {t1a {128 1} t1b {128 64}}
+
+# Change the t1.b values all back to NULL.  Add columns t1.c and t1.d.
+# Create a multi-column indices using t1.b and verify that ANALYZE 
+# processes them correctly.
+#
+do_test analyze4-1.3 {
+  db eval {
+    UPDATE t1 SET b=NULL;
+    ALTER TABLE t1 ADD COLUMN c;
+    ALTER TABLE t1 ADD COLUMN d;
+    UPDATE t1 SET c=a/4, d=a/2;
+    CREATE INDEX t1bcd ON t1(b,c,d);
+    CREATE INDEX t1cdb ON t1(c,d,b);
+    CREATE INDEX t1cbd ON t1(c,b,d);
+    ANALYZE;
+    SELECT idx, stat FROM sqlite_stat1 WHERE tbl='t1' ORDER BY idx;
+  }
+} {t1a {128 1} t1b {128 128} t1bcd {128 128 4 2} t1cbd {128 4 4 2} t1cdb {128 4 2 2}}
+
+# Verify that collating sequences are taken into account when computing
+# ANALYZE statistics.
+#
+do_test analyze4-2.0 {
+  db eval {
+    CREATE TABLE t2(
+      x INTEGER PRIMARY KEY,
+      a TEXT COLLATE nocase,
+      b TEXT COLLATE rtrim,
+      c TEXT COLLATE binary
+    );
+    CREATE INDEX t2a ON t2(a);
+    CREATE INDEX t2b ON t2(b);
+    CREATE INDEX t2c ON t2(c);
+    CREATE INDEX t2c2 ON t2(c COLLATE nocase);
+    CREATE INDEX t2c3 ON t2(c COLLATE rtrim);
+    INSERT INTO t2 VALUES(1, 'abc', 'abc', 'abc');
+    INSERT INTO t2 VALUES(2, 'abC', 'abC', 'abC');
+    INSERT INTO t2 VALUES(3, 'abc ', 'abc ', 'abc ');
+    INSERT INTO t2 VALUES(4, 'abC ', 'abC ', 'abC ');
+    INSERT INTO t2 VALUES(5, 'aBc', 'aBc', 'aBc');
+    INSERT INTO t2 VALUES(6, 'aBC', 'aBC', 'aBC');
+    INSERT INTO t2 VALUES(7, 'aBc ', 'aBc ', 'aBc ');
+    INSERT INTO t2 VALUES(8, 'aBC ', 'aBC ', 'aBC ');
+    ANALYZE;
+    SELECT idx, stat FROM sqlite_stat1 WHERE tbl='t2' ORDER BY idx;
+  }
+} {t2a {8 4} t2b {8 2} t2c {8 1} t2c2 {8 4} t2c3 {8 2}}
+
+finish_test