MDEV-38305: Expose adaptive hash index statistics in ANALYZE FORMAT=JSON

mysql-test/include/analyze-format.inc

@@ -4,4 +4,4 @@
 # - r_engine_stats depends on buffer pool state and whether old record versions
 #   were purged.
 
---replace_regex /("(r_[a-z_]*_time(_in_progress)?_ms|r_buffer_size|cost|r_partial_match_buffer_size)": )[^, \n]*/\1"REPLACED"/ /("r_engine_stats":) {[^}]*}/\1 REPLACED/
+--replace_regex /("(r_[a-z_]*_time(_in_progress)?_ms|r_buffer_size|cost|r_partial_match_buffer_size)": )[^, \n]*/\1"REPLACED"/ /("r_engine_stats":) \{(?:[^{}]|\{[^}]*\})*\}/\1 REPLACED/

mysql-test/main/rowid_filter_innodb,ahi.rdiff

@@ -9,21 +9,53 @@
  DROP DATABASE IF EXISTS dbt3_s001;
  CREATE DATABASE dbt3_s001;
  use dbt3_s001;
-@@ -2059,7 +2059,7 @@
+@@ -2061,7 +2061,11 @@
            "r_table_time_ms": "REPLACED",
            "r_other_time_ms": "REPLACED",
            "r_engine_stats": {
 -            "pages_accessed": 90
-+            "pages_accessed": 51
++            "pages_accessed": 51,
++            "r_ahi_stats": {
++              "ahi_searches": 39,
++              "ahi_searches_btree": 3
++            }
            },
            "filtered": "REPLACED",
            "r_total_filtered": 2.43902439,
-@@ -2227,7 +2227,7 @@
+@@ -2093,7 +2097,10 @@
+           "r_table_time_ms": "REPLACED",
+           "r_other_time_ms": "REPLACED",
+           "r_engine_stats": {
+-            "pages_accessed": 4
++            "pages_accessed": 4,
++            "r_ahi_stats": {
++              "ahi_searches_btree": 1
++            }
+           },
+           "filtered": "REPLACED",
+           "r_total_filtered": 66.66666667,
+@@ -2229,7 +2236,11 @@
            "r_table_time_ms": "REPLACED",
            "r_other_time_ms": "REPLACED",
            "r_engine_stats": {
 -            "pages_accessed": 90
-+            "pages_accessed": 49
++            "pages_accessed": 49,
++            "r_ahi_stats": {
++              "ahi_searches": 41,
++              "ahi_searches_btree": 1
++            }
            },
            "filtered": "REPLACED",
            "r_total_filtered": 2.43902439,
+@@ -2261,7 +2272,10 @@
+           "r_table_time_ms": "REPLACED",
+           "r_other_time_ms": "REPLACED",
+           "r_engine_stats": {
+-            "pages_accessed": 4
++            "pages_accessed": 4,
++            "r_ahi_stats": {
++              "ahi_searches_btree": 1
++            }
+           },
+           "filtered": "REPLACED",
+           "r_total_filtered": 66.66666667,

mysql-test/suite/innodb/include/check_ahi_status.inc

@@ -0,0 +1,45 @@
+# Include file to execute a query with optional repetition and display
+# values of r_ahi_stats on ANALYZE FORMAT=JSON
+#
+# Parameters:
+#   $query - The query to execute
+#   $repeat - Number of times to repeat the query before analyzing
+#
+# This include file will:
+# 1. Execute the query $repeat times to warm up AHI (with logging disabled)
+# 2. Execute ANALYZE FORMAT=JSON on the query and display the values
+
+--disable_query_log
+--disable_result_log
+
+# Repeat the query to warm up AHI
+let $i = $repeat;
+while ($i > 0)
+{
+  eval $query;
+  dec $i;
+}
+
+--enable_result_log
+--enable_query_log
+
+# Execute ANALYZE FORMAT=JSON once and capture output
+--echo ANALYZE FORMAT=JSON $query
+let $out=`ANALYZE FORMAT=JSON $query`;
+
+# Parse JSON and extract AHI variables
+--disable_query_log
+evalp set @js='$out';
+set @ahi_searches = COALESCE(json_extract(@js,'$**.r_engine_stats.r_ahi_stats.ahi_searches'), 0);
+set @ahi_searches_btree = COALESCE(json_extract(@js,'$**.r_engine_stats.r_ahi_stats.ahi_searches_btree'), 0);
+set @ahi_rows_added = COALESCE(json_extract(@js,'$**.r_engine_stats.r_ahi_stats.ahi_rows_added'), 0);
+set @ahi_pages_added = COALESCE(json_extract(@js,'$**.r_engine_stats.r_ahi_stats.ahi_pages_added'), 0);
+set @r_rows = json_extract(@js,'$**.table.r_rows');
+
+# Display AHI variables
+select @ahi_searches as ahi_searches,
+       @ahi_searches_btree as ahi_searches_btree,
+       @ahi_rows_added as ahi_rows_added,
+       @ahi_pages_added as ahi_pages_added,
+       @r_rows as r_rows;
+--enable_query_log

mysql-test/suite/innodb/r/ahi_stats.result

@@ -0,0 +1,30 @@
+#
+# MDEV 38305 : Expose adaptive hash index statistics in ANALYZE FORMAT=JSON
+#
+SET @start_global_value= @@global.innodb_adaptive_hash_index;
+SET GLOBAL innodb_adaptive_hash_index= ON;
+CREATE TABLE t1 (
+id INT PRIMARY KEY,
+col1 INT,
+col2 INT,
+col3 INT,
+INDEX idx_1 (col1),
+INDEX idx_2 (col2),
+INDEX idx_3 (col3)
+) ENGINE=InnoDB;
+INSERT INTO t1 SELECT seq, seq % 20, seq % 5, seq % 10 FROM seq_0_to_999;
+ANALYZE FORMAT=JSON SELECT * FROM t1 FORCE INDEX(idx_1) WHERE col1 = 5
+ahi_searches	ahi_searches_btree	ahi_rows_added	ahi_pages_added	r_rows
+0	[51]	0	0	[50]
+ANALYZE FORMAT=JSON SELECT * FROM t1 FORCE INDEX(idx_2) WHERE col2 = 3
+ahi_searches	ahi_searches_btree	ahi_rows_added	ahi_pages_added	r_rows
+[129]	[72]	[797]	[2]	[200]
+ANALYZE FORMAT=JSON SELECT * FROM t1 FORCE INDEX(idx_3) WHERE col3 = 5
+ahi_searches	ahi_searches_btree	ahi_rows_added	ahi_pages_added	r_rows
+[101]	0	0	0	[100]
+SET GLOBAL innodb_adaptive_hash_index = OFF;
+ANALYZE FORMAT=JSON SELECT * FROM t1 FORCE INDEX(idx_2) WHERE col2 = 2
+ahi_searches	ahi_searches_btree	ahi_rows_added	ahi_pages_added	r_rows
+0	0	0	0	[200]
+DROP TABLE t1;
+SET GLOBAL innodb_adaptive_hash_index= @start_global_value;

mysql-test/suite/innodb/r/innodb_skip_innodb_is_tables.result

@@ -188,9 +188,9 @@ index_page_reorg_successful	index	0	NULL	NULL	NULL	0	NULL	NULL	NULL	NULL	NULL	NU
 index_page_discards	index	0	NULL	NULL	NULL	0	NULL	NULL	NULL	NULL	NULL	NULL	NULL	0	counter	Number of index pages discarded
 adaptive_hash_searches	adaptive_hash_index	0	NULL	NULL	NULL	0	NULL	NULL	NULL	NULL	NULL	NULL	NULL	0	status_counter	Number of successful searches using Adaptive Hash Index
 adaptive_hash_searches_btree	adaptive_hash_index	0	NULL	NULL	NULL	0	NULL	NULL	NULL	NULL	NULL	NULL	NULL	0	status_counter	Number of searches using B-tree on an index search
-adaptive_hash_pages_added	adaptive_hash_index	0	NULL	NULL	NULL	0	NULL	NULL	NULL	NULL	NULL	NULL	NULL	0	counter	Number of index pages on which the Adaptive Hash Index is built
+adaptive_hash_pages_added	adaptive_hash_index	0	NULL	NULL	NULL	0	NULL	NULL	NULL	NULL	NULL	NULL	NULL	0	status_counter	Number of index pages on which the Adaptive Hash Index is built
 adaptive_hash_pages_removed	adaptive_hash_index	0	NULL	NULL	NULL	0	NULL	NULL	NULL	NULL	NULL	NULL	NULL	0	counter	Number of index pages whose corresponding Adaptive Hash Index entries were removed
-adaptive_hash_rows_added	adaptive_hash_index	0	NULL	NULL	NULL	0	NULL	NULL	NULL	NULL	NULL	NULL	NULL	0	counter	Number of Adaptive Hash Index rows added
+adaptive_hash_rows_added	adaptive_hash_index	0	NULL	NULL	NULL	0	NULL	NULL	NULL	NULL	NULL	NULL	NULL	0	status_counter	Number of Adaptive Hash Index rows added
 adaptive_hash_rows_removed	adaptive_hash_index	0	NULL	NULL	NULL	0	NULL	NULL	NULL	NULL	NULL	NULL	NULL	0	counter	Number of Adaptive Hash Index rows removed
 adaptive_hash_rows_deleted_no_hash_entry	adaptive_hash_index	0	NULL	NULL	NULL	0	NULL	NULL	NULL	NULL	NULL	NULL	NULL	0	counter	Number of rows deleted that did not have corresponding Adaptive Hash Index entries
 adaptive_hash_rows_updated	adaptive_hash_index	0	NULL	NULL	NULL	0	NULL	NULL	NULL	NULL	NULL	NULL	NULL	0	counter	Number of Adaptive Hash Index rows updated

mysql-test/suite/innodb/r/innodb_status_variables.result

@@ -5,6 +5,8 @@ AND variable_name NOT IN
 'INNODB_MEM_ADAPTIVE_HASH',
 'INNODB_BUFFERED_AIO_SUBMITTED','INNODB_BUFFER_POOL_PAGES_LATCHED');
 variable_name
+INNODB_ADAPTIVE_HASH_PAGES_ADDED
+INNODB_ADAPTIVE_HASH_ROWS_ADDED
 INNODB_ASYNC_READS_PENDING
 INNODB_ASYNC_READS_TASKS_RUNNING
 INNODB_ASYNC_READS_TOTAL_COUNT

mysql-test/suite/innodb/t/ahi_stats.test

@@ -0,0 +1,78 @@
+--source include/have_innodb.inc
+--source include/have_innodb_16k.inc
+--source include/have_sequence.inc
+
+--echo #
+--echo # MDEV 38305 : Expose adaptive hash index statistics in ANALYZE FORMAT=JSON
+--echo #
+
+# Test Plan:
+# When queries use secondary indexes, InnoDB must lookup clustered index records
+# using the primary key reference obtained from the secondary index. These
+# clustered index lookups accumulate and trigger AHI building when a threshold
+# is reached. This test verifies that AHI statistics are correctly reported in
+# ANALYZE FORMAT=JSON output across different scenarios:
+#
+# Test 1: Access 50 rows (col1=5, 50 matches) - insufficient to build AHI
+# Test 2: Access 200 rows (col2=3, 200 matches) - combined with Test 1 (250 total),
+#         this triggers AHI construction on the clustered index
+# Test 3: Access with heavy warmup (100 repetitions) - AHI fully utilized
+# Test 4: AHI disabled - verify statistics are zero regardless of access patterns
+
+SET @start_global_value= @@global.innodb_adaptive_hash_index;
+SET GLOBAL innodb_adaptive_hash_index= ON;
+
+CREATE TABLE t1 (
+  id INT PRIMARY KEY,
+  col1 INT,
+  col2 INT,
+  col3 INT,
+  INDEX idx_1 (col1),
+  INDEX idx_2 (col2),
+  INDEX idx_3 (col3)
+) ENGINE=InnoDB;
+
+INSERT INTO t1 SELECT seq, seq % 20, seq % 5, seq % 10 FROM seq_0_to_999;
+
+# Test 1: Insufficient accesses to build AHI
+# Query accesses 50 rows (col1=5 matches 50 out of 1000 rows: 5,25,45,...,985).
+# When using idx_1, InnoDB performs 50 clustered index lookups to retrieve the
+# full rows. This is insufficient to trigger AHI construction, so AHI statistics
+# should show minimal or no AHI activity.
+let $query = SELECT * FROM t1 FORCE INDEX(idx_1) WHERE col1 = 5;
+let $repeat = 0;
+--source suite/innodb/include/check_ahi_status.inc
+
+# Test 2: Accumulated accesses trigger AHI construction
+# Query accesses 200 rows (col2=3 matches 200 out of 1000 rows: 3,8,13,18,...,998).
+# Combined with Test 1's 50 clustered index lookups, the accumulated total of 250
+# clustered index searches crosses the threshold to build AHI. This test verifies
+# that AHI statistics reflect the construction and initial usage of the hash index.
+let $query = SELECT * FROM t1 FORCE INDEX(idx_2) WHERE col2 = 3;
+let $repeat = 0;
+--source suite/innodb/include/check_ahi_status.inc
+
+# Test 3: Verify AHI statistics with heavy warmup (AHI fully utilized)
+# Query accesses 100 rows (col3=5 matches 100 out of 1000 rows: 5,15,25,...,995).
+# With repeat=200, this executes the query 200 times before the ANALYZE, resulting
+# in 20,000 clustered index lookups. This heavy access pattern ensures the AHI is
+# fully built and actively serving lookups, allowing verification that AHI hit
+# statistics are properly reported when the hash index is effectively utilized.
+let $query = SELECT * FROM t1 FORCE INDEX(idx_3) WHERE col3 = 5;
+let $repeat = 200;
+--source suite/innodb/include/check_ahi_status.inc
+
+# Test 4: Verify AHI statistics when AHI is disabled
+# Query accesses 200 rows (col2=2 matches 200 out of 1000 rows: 2,7,12,...,997).
+# With repeat=100, this would normally trigger heavy AHI usage (20,000 clustered
+# index lookups). However, since innodb_adaptive_hash_index is turned OFF, the AHI
+# is not used and all AHI statistics should be zero regardless of query repetition.
+SET GLOBAL innodb_adaptive_hash_index = OFF;
+
+let $query = SELECT * FROM t1 FORCE INDEX(idx_2) WHERE col2 = 2;
+let $repeat = 100;
+--source suite/innodb/include/check_ahi_status.inc
+
+# Cleanup
+DROP TABLE t1;
+SET GLOBAL innodb_adaptive_hash_index= @start_global_value;

sql/ha_handler_stats.h

@@ -41,6 +41,11 @@ class ha_handler_stats
 
   ulonglong undo_records_read;
 
+  ulonglong ahi_searches;  /* Successful adaptive hash lookups */
+  ulonglong ahi_searches_btree;  /* B-tree searches (AHI miss) */
+  ulonglong ahi_rows_added;  /* Rows added to adaptive hash index */
+  ulonglong ahi_pages_added;  /* Pages added to adaptive hash index */
+
   /* Time spent in engine, in timer_tracker_frequency() units */
   ulonglong engine_time;
 

sql/sql_explain.cc

@@ -1952,6 +1952,20 @@ static void trace_engine_stats(handler *file, Json_writer *writer)
       writer->add_member("pages_prefetch_read_count").add_ull(hs->pages_prefetched);
     if (hs->undo_records_read)
       writer->add_member("old_rows_read").add_ull(hs->undo_records_read);
+    if (unlikely(hs->ahi_searches | hs->ahi_searches_btree |
+        hs->ahi_rows_added | hs->ahi_pages_added))
+    {
+      writer->add_member("r_ahi_stats").start_object();
+      if (hs->ahi_searches)
+        writer->add_member("ahi_searches").add_ull(hs->ahi_searches);
+      if (hs->ahi_searches_btree)
+        writer->add_member("ahi_searches_btree").add_ull(hs->ahi_searches_btree);
+      if (hs->ahi_rows_added)
+        writer->add_member("ahi_rows_added").add_ull(hs->ahi_rows_added);
+      if (hs->ahi_pages_added)
+        writer->add_member("ahi_pages_added").add_ull(hs->ahi_pages_added);
+      writer->end_object();
+    }
     writer->end_object();
   }
 }

storage/innobase/btr/btr0btr.cc

@@ -1888,7 +1888,7 @@ btr_root_raise_and_insert(
 				page_get_infimum_rec(root->page.frame));
 		}
 
-		btr_search_move_or_delete_hash_entries(new_block, root);
+		btr_search_move_or_delete_hash_entries(new_block, root, *mtr);
 	}
 
 	constexpr uint16_t max_trx_id = PAGE_HEADER + PAGE_MAX_TRX_ID;
@@ -3064,7 +3064,7 @@ btr_page_split_and_insert(
 			}
 
 			btr_search_move_or_delete_hash_entries(
-				new_block, block);
+				new_block, block, *mtr);
 
 			/* Delete the records from the source page. */
 
@@ -3112,7 +3112,7 @@ btr_page_split_and_insert(
 			}
 
 			btr_search_move_or_delete_hash_entries(
-				new_block, block);
+				new_block, block, *mtr);
 
 			/* Delete the records from the source page. */
 
@@ -3460,7 +3460,7 @@ btr_lift_page_up(
 			lock_prdt_rec_move(father_block, block->page.id());
 		} else {
 			btr_search_move_or_delete_hash_entries(
-				father_block, block);
+				father_block, block, *mtr);
 		}
 	}