From 0c51d54b66313228223273f26e256b26eb66622d Mon Sep 17 00:00:00 2001
From: Aakash Arayambeth <aarayambeth@bloomberg.net>
Date: Thu, 5 Dec 2024 13:48:53 -0500
Subject: [PATCH] Fix bugs in analyze_empty_tables behavior

---
 sqlite/src/analyze.c           | 10 ++++-----
 tests/analyze.test/t16.req     |  0
 tests/analyze.test/t16.req.out | 10 +++++++++
 tests/analyze.test/t16.sh      | 39 ++++++++++++++++++++++++++++++++++
 tests/analyze.test/t16.tool    |  1 +
 5 files changed, 55 insertions(+), 5 deletions(-)
 create mode 100755 tests/analyze.test/t16.req
 create mode 100755 tests/analyze.test/t16.req.out
 create mode 100755 tests/analyze.test/t16.sh
 create mode 100755 tests/analyze.test/t16.tool

diff --git a/sqlite/src/analyze.c b/sqlite/src/analyze.c
index a12e06a8ff..1ac5857de4 100644
--- a/sqlite/src/analyze.c
+++ b/sqlite/src/analyze.c
@@ -1575,6 +1575,11 @@ static void analyzeOneTable(
       }
 #endif /* defined(SQLITE_BUILDING_FOR_COMDB2) */
       addrNext = sqlite3VdbeCurrentAddr(v);
+#if defined(SQLITE_BUILDING_FOR_COMDB2)
+      if( sqlite3_gbl_tunables.analyze_empty_tables ){
+        sqlite3VdbeJumpHere(v, addrRewind);
+      }
+#endif /* defined(SQLITE_BUILDING_FOR_COMDB2) */
 #if !defined(SQLITE_BUILDING_FOR_COMDB2)
       callStatGet(v, regStat4, STAT_GET_ROWID, regSampleRowid);
       addrIsNull = sqlite3VdbeAddOp1(v, OP_IsNull, regSampleRowid);
@@ -1606,11 +1611,6 @@ static void analyzeOneTable(
       sqlite3VdbeAddOp3(v, OP_Insert, iStatCur+1, regTemp, regNewRowid);
       sqlite3VdbeAddOp2(v, OP_Goto, 1, addrNext); /* P1==1 for end-of-loop */
       sqlite3VdbeJumpHere(v, addrIsNull);
-#if defined(SQLITE_BUILDING_FOR_COMDB2)
-      if( sqlite3_gbl_tunables.analyze_empty_tables ){
-        sqlite3VdbeJumpHere(v, addrRewind);
-      }
-#endif /* defined(SQLITE_BUILDING_FOR_COMDB2) */
     }
 #endif /* SQLITE_ENABLE_STAT3_OR_STAT4 */
 
diff --git a/tests/analyze.test/t16.req b/tests/analyze.test/t16.req
new file mode 100755
index 0000000000..e69de29bb2
diff --git a/tests/analyze.test/t16.req.out b/tests/analyze.test/t16.req.out
new file mode 100755
index 0000000000..16e121c6f0
--- /dev/null
+++ b/tests/analyze.test/t16.req.out
@@ -0,0 +1,10 @@
+(count(*)=0)
+(count(*)=0)
+TURNING ON ANALYZE EMPTY TABLES
+(count(*)=1)
+(count(*)=1)
+INSERTING RECORDS
+(rows inserted=50000)
+RUNNING ANALYZE
+(count(*)=1)
+(count(*)=24)
diff --git a/tests/analyze.test/t16.sh b/tests/analyze.test/t16.sh
new file mode 100755
index 0000000000..c23b1a6030
--- /dev/null
+++ b/tests/analyze.test/t16.sh
@@ -0,0 +1,39 @@
+#!/bin/bash
+
+function purge_stats
+{
+    ${CDB2SQL_EXE} ${CDB2_OPTIONS} ${DBNAME} local "truncate sqlite_stat1"
+    ${CDB2SQL_EXE} ${CDB2_OPTIONS} ${DBNAME} local "truncate sqlite_stat4"
+}
+function count_stats 
+{
+    ${CDB2SQL_EXE} ${CDB2_OPTIONS} ${DBNAME} local "select count(*) from sqlite_stat1"
+    ${CDB2SQL_EXE} ${CDB2_OPTIONS} ${DBNAME} local "select count(*) from sqlite_stat4"
+}
+
+purge_stats
+#default behavior
+${CDB2SQL_EXE} ${CDB2_OPTIONS} ${DBNAME} local "DROP TABLE IF EXISTS empty"
+${CDB2SQL_EXE} ${CDB2_OPTIONS} ${DBNAME} local "CREATE TABLE empty(a int primary key)"
+${CDB2SQL_EXE} ${CDB2_OPTIONS} ${DBNAME} local "ANALYZE empty"
+count_stats
+
+echo "TURNING ON ANALYZE EMPTY TABLES"
+${CDB2SQL_EXE} ${CDB2_OPTIONS} ${DBNAME} local "exec procedure sys.cmd.send('setsqlattr analyze_empty_tables on')"
+purge_stats
+${CDB2SQL_EXE} ${CDB2_OPTIONS} ${DBNAME} local "ANALYZE empty"
+count_stats
+
+echo "INSERTING RECORDS"
+${CDB2SQL_EXE} ${CDB2_OPTIONS} ${DBNAME} local "INSERT INTO EMPTY SELECT * FROM generate_series(0,49999)"
+echo "RUNNING ANALYZE"
+purge_stats
+${CDB2SQL_EXE} ${CDB2_OPTIONS} ${DBNAME} local "ANALYZE empty"
+count_stats
+
+echo "TURNING OFF ANALYZE EMPTY TABLES"
+${CDB2SQL_EXE} ${CDB2_OPTIONS} ${DBNAME} local "exec procedure sys.cmd.send('setsqlattr analyze_empty_tables off')"
+echo "RUNNING ANALYZE"
+purge_stats
+${CDB2SQL_EXE} ${CDB2_OPTIONS} ${DBNAME} local "ANALYZE empty"
+count_stats
diff --git a/tests/analyze.test/t16.tool b/tests/analyze.test/t16.tool
new file mode 100755
index 0000000000..3fd0e4ac39
--- /dev/null
+++ b/tests/analyze.test/t16.tool
@@ -0,0 +1 @@
+t16.sh