WL#3363: ndb$info
Status: Complete
We hear a lot of demand for "more monitoring" for NDB. Sometimes there's some
ideas about what people want, sometimes not. We aim for a generic interface that
makes it easy for NDB coders to add information and easy for users, support or
developers to access this information.
For the initial implementation, speed is not a priority.
Existing information:
- some statistics can be gotten from various DUMP numbers
- stored in variables inside ndbd or can be easily computed.
Proposed interface:
- table accessible from SQL so that users can just SELECT from it.
- Also simple interface from ndb_mgm to easily "query" ndb$info tables from
command line (basically a SELECT * FROM X without a where clause)
common HOWTO impl:
1) Data structure for (statically) specifying NDB$INFO tables (no need to
allocate memory)
2) code for generating CREATE TABLE statements from structure (run these in
mysqld to get FRM files)
3) global list of NDB$INFO tables for node
mgmd HOWTO impl:
1) new "ndbinfo" protocol command.
2) export some information from mgmd (would be good to query even if cluster not up)
a) log destinations/status
b) current session information (list sessions/show sessions)
c) configuration information (all nodes should output this)
Kernel HOWTO impl:
1) Create new block Dbinfo
Which has a simple scan like interface
GSN_GET_INFO_REQ
GSN_GET_NEXT_INFO_REQ
2) Create new ndbapi interface for scanning
3) Create ndb$tables
mysqld HOWTO impl:
4) Create new handler ndbinfo
rnd_init
rnd_next
create
5) Create frm files for ndb$tables
----
key points:
1) new block + new signal interface + new ndbapi interface
2) new handler for accessing
Test plan (in development)
https://inside.mysql.com/wiki/ClusterNdbInfoTestPlan
----
SQL interface to NDB$INFO, take 2 By Martin
Subject:
SQL interface to NDB$INFO, take 2
From:
Martin Skold
Date:
Tue, 03 Feb 2009 09:41:54 +0100
To:
dev-ndb
A new version of the SQL interface to NDB$INFO has been committed.
http://lists.mysql.com/commits/64925
The actual tables in NDB$INFO have not been changed, this can now
be an open discussion on what they should contain.
Here is a summary of what it contains:
- An extension of the Ndb API with a new meta-data
type NdbDictionary::InfoTable and a new operation
NdbInfoScanOperation. Instead of using transactions
a NdbInfoHandle is used to connect.
- A new pluggable storage engine, ha_ndbcluster_info,
has been implemented that provides an SQL interface
to NDB$INFO tables
(using the new NdbInfoScan interface in the NdbAPI).
- The engine currently needs to be installed manually
by the user (INSTALL PLUGIN). This will create the
database NDB$INFO (if not already created).
Some improvements include:
- A utility script can be created by executing the
program ndbinfo_bootstrap. This will load the plugin
and create all the tables along with a utility table
that maps BLOCK_NUMBER to BLOCK_NAME.
- In ha_ndbcluster_info::open a check has been added verifies
that kernel definition of table and mysql table are compatible.
(Iterates all fields and compares field types with what NDB$INFO
assumes).
- Tables can be upgraded by dropping frm files and doing a
show tables; command (or manually redefining them using output
from newly built ndbinfo_bootstrap).
To build and run the new interface:
In storage/ha_ndbcluster_info/ :
make install
This will install the plugin in the directory:
:=/lib/mysql/plugin
A utility program is also created that outputs SQL commands:
ndbinfo_bootstrap
Start mysqld with the following flag:
--plugin_dir=
Run the SQL commands from ndbinfo_bootstrap:
mysql> CREATE DATABASE IF NOT EXISTS NDB$INFO;
Query OK, 1 row affected (0.21 sec)
mysql> INSTALL PLUGIN ndbcluster_info SONAME 'ha_ndbcluster_info.so';
Query OK, 0 rows affected, 1 warning (0.01 sec)
...
The new tables can be found in database NDB$INFO:
mysql> use NDB$INFO;
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A
Database changed
mysql> show tables;
+--------------------+
| Tables_in_NDB$INFO |
+--------------------+
| BACKUP_PARAMETERS |
| BACKUP_RECORDS |
| BLOCK_NAME |
| COLUMNS |
| LOGDESTINATION |
| MEMUSAGE |
| POOLS |
| TABLES |
+--------------------+
8 rows in set (0.14 sec)
mysql> select * from MEMUSAGE;
+---------------+---------+--------------+------------+-------------+--------------+
| RESOURCE_NAME | NODE_ID | PAGE_SIZE_KB | PAGES_USED | PAGES_TOTAL | BLOCK_NUMBER |
+---------------+---------+--------------+------------+-------------+--------------+
| IndexMemory | 1 | 0 | 17 | 544 | 248 |
| DataMemory | 1 | 0 | 6 | 640 | 249 |
| IndexMemory | 2 | 0 | 17 | 544 | 248 |
| DataMemory | 2 | 0 | 6 | 640 | 249 |
+---------------+---------+--------------+------------+-------------+--------------+
4 rows in set (0.02 sec)
mysql> select BLOCK_NAME, m.* from BLOCK_NAME b, MEMUSAGE m where b.BLOCK_NUMBER
= m.BLOCK_NUMBER;
+------------+---------------+---------+--------------+------------+-------------+--------------+
| BLOCK_NAME | RESOURCE_NAME | NODE_ID | PAGE_SIZE_KB | PAGES_USED | PAGES_TOTAL
| BLOCK_NUMBER |
+------------+---------------+---------+--------------+------------+-------------+--------------+
| DBACC | IndexMemory | 1 | 0 | 17 | 544 |
248 |
| DBTUP | DataMemory | 1 | 0 | 6 | 640 |
249 |
| DBACC | IndexMemory | 2 | 0 | 17 | 544 |
248 |
| DBTUP | DataMemory | 2 | 0 | 6 | 640 |
249 |
+------------+---------------+---------+--------------+------------+-------------+--------------+
4 rows in set (0.03 sec)
mysql> select * from POOLS;
+---------+--------+-------------------------+-------+------------+
| NODE_ID | BLOCK | POOL_NAME | FREE | SIZE |
+---------+--------+-------------------------+-------+------------+
| 1 | DBTUP | Scan Lock | 32832 | 32832 |
| 1 | DBTUP | Scan Operation | 513 | 514 |
| 1 | DBTUP | Trigger | 1001 | 1010 |
| 1 | DBTUP | Stored Proc | 513 | 513 |
| 1 | DBTUP | Build Index | 32 | 32 |
| 1 | DBTUP | Operation | 0 | 11050 |
| 1 | DBTUP | Page | 0 | 4294967295 |
| 1 | BACKUP | Backup Record | 1 | 2 |
| 1 | BACKUP | Backup File | 3 | 4 |
| 1 | BACKUP | Table | 323 | 323 |
| 1 | BACKUP | Trigger | 966 | 966 |
| 1 | BACKUP | Fragment | 1289 | 1289 |
| 1 | BACKUP | Page | 137 | 201 |
| 1 | DBTC | Defined Trigger | 1010 | 1010 |
| 1 | DBTC | Fired Trigger | 4000 | 4000 |
| 1 | DBTC | Index | 322 | 322 |
| 1 | DBTC | Scan Fragment | 513 | 513 |
| 1 | DBTC | Commit ACK Marker | 0 | 0 |
| 1 | DBTC | Index Op | 0 | 0 |
| 1 | SUMA | Subscriber | 254 | 260 |
| 1 | SUMA | Table | 127 | 130 |
| 1 | SUMA | Subscription | 127 | 130 |
| 1 | SUMA | Sync | 2 | 2 |
| 1 | SUMA | Data Buffer | 2057 | 2057 |
| 1 | SUMA | SubOp | 0 | 0 |
| 1 | SUMA | Page Chunk | 49 | 50 |
| 1 | SUMA | GCP | 1210 | 1210 |
| 1 | DBUTIL | Page | 10 | 10 |
| 1 | DBUTIL | Prepare | 1 | 1 |
| 1 | DBUTIL | Prepared Operation | 2 | 6 |
| 1 | DBUTIL | Operation | 64 | 64 |
| 1 | DBUTIL | Transaction | 32 | 32 |
| 1 | DBUTIL | Attribute Mapping | 100 | 100 |
| 1 | DBUTIL | Data Buffer | 5997 | 6000 |
| 1 | TRIX | Attribute Order Buffer | 100 | 100 |
| 1 | TRIX | Subscription Record | 100 | 100 |
| 1 | DBTC | Index | 0 | 322 |
| 1 | DBTC | Fragment | 0 | 0 |
| 1 | DBTC | Descriptor page | 6 | 6 |
| 1 | DBTC | Fragment Operation | 8 | 8 |
| 1 | DBTC | Scan Operation | 513 | 513 |
| 1 | DBTC | Scan Bound | 14364 | 14364 |
| 1 | DBTC | Scan Lock | 32832 | 32832 |
| 1 | DBDICT | Attribute Record | 2028 | 2057 |
| 1 | DBDICT | Table Record | 0 | 322 |
| 1 | DBDICT | Trigger Record | 0 | 1010 |
| 1 | DBDICT | FS Connect Record | 4 | 4 |
| 1 | DBDICT | DictObject | 1326 | 1332 |
| 1 | DBDICT | Schema Operation | 0 | 0 |
| 1 | DBDICT | Schema Transaction | 5 | 5 |
| 1 | DBDICT | Transaction Handle | 2 | 2 |
| 1 | DBDICT | Create Table Record | 32 | 32 |
| 1 | DBDICT | Drop Table Record | 32 | 32 |
| 1 | DBDICT | Alter Table Record | 32 | 32 |
| 1 | DBDICT | Create Index Record | 32 | 32 |
| 1 | DBDICT | Drop Index Record | 32 | 32 |
| 1 | DBDICT | Alter Index Record | 32 | 32 |
| 1 | DBDICT | Build Index Record | 32 | 32 |
| 1 | DBDICT | Create Hash Map Record | 32 | 32 |
| 1 | DBDICT | Copy Data Record | 32 | 32 |
| 1 | DBDICT | Create Trigger Record | 32 | 32 |
| 1 | DBDICT | Drop Trigger Record | 32 | 32 |
| 1 | DBDICT | Create Filegroup Record | 32 | 32 |
| 1 | DBDICT | Create File Record | 32 | 32 |
| 1 | DBDICT | Drop Filegroup Record | 32 | 32 |
| 1 | DBDICT | Drop File Record | 32 | 32 |
| 1 | DBDICT | Operation Record | 0 | 0 |
| 2 | DBTUP | Scan Lock | 32832 | 32832 |
| 2 | DBTUP | Scan Operation | 513 | 514 |
| 2 | DBTUP | Trigger | 1001 | 1010 |
| 2 | DBTUP | Stored Proc | 513 | 513 |
| 2 | DBTUP | Build Index | 32 | 32 |
| 2 | DBTUP | Operation | 0 | 11050 |
| 2 | DBTUP | Page | 0 | 4294967295 |
| 2 | BACKUP | Backup Record | 1 | 2 |
| 2 | BACKUP | Backup File | 3 | 4 |
| 2 | BACKUP | Table | 323 | 323 |
| 2 | BACKUP | Trigger | 966 | 966 |
| 2 | BACKUP | Fragment | 1289 | 1289 |
| 2 | BACKUP | Page | 137 | 201 |
| 2 | DBTC | Defined Trigger | 1010 | 1010 |
| 2 | DBTC | Fired Trigger | 4000 | 4000 |
| 2 | DBTC | Index | 322 | 322 |
| 2 | DBTC | Scan Fragment | 513 | 513 |
| 2 | DBTC | Commit ACK Marker | 0 | 0 |
| 2 | DBTC | Index Op | 0 | 0 |
| 2 | SUMA | Subscriber | 254 | 260 |
| 2 | SUMA | Table | 127 | 130 |
| 2 | SUMA | Subscription | 127 | 130 |
| 2 | SUMA | Sync | 2 | 2 |
| 2 | SUMA | Data Buffer | 2057 | 2057 |
| 2 | SUMA | SubOp | 0 | 0 |
| 2 | SUMA | Page Chunk | 49 | 50 |
| 2 | SUMA | GCP | 1210 | 1210 |
| 2 | DBUTIL | Page | 10 | 10 |
| 2 | DBUTIL | Prepare | 1 | 1 |
| 2 | DBUTIL | Prepared Operation | 2 | 6 |
| 2 | DBUTIL | Operation | 64 | 64 |
| 2 | DBUTIL | Transaction | 32 | 32 |
| 2 | DBUTIL | Attribute Mapping | 100 | 100 |
| 2 | DBUTIL | Data Buffer | 5997 | 6000 |
| 2 | TRIX | Attribute Order Buffer | 100 | 100 |
| 2 | TRIX | Subscription Record | 100 | 100 |
| 2 | DBTC | Index | 0 | 322 |
| 2 | DBTC | Fragment | 0 | 0 |
| 2 | DBTC | Descriptor page | 6 | 6 |
| 2 | DBTC | Fragment Operation | 8 | 8 |
| 2 | DBTC | Scan Operation | 513 | 513 |
| 2 | DBTC | Scan Bound | 14364 | 14364 |
| 2 | DBTC | Scan Lock | 32832 | 32832 |
| 2 | DBDICT | Attribute Record | 2028 | 2057 |
| 2 | DBDICT | Table Record | 0 | 322 |
| 2 | DBDICT | Trigger Record | 0 | 1010 |
| 2 | DBDICT | FS Connect Record | 4 | 4 |
| 2 | DBDICT | DictObject | 1326 | 1332 |
| 2 | DBDICT | Schema Operation | 0 | 0 |
| 2 | DBDICT | Schema Transaction | 5 | 5 |
| 2 | DBDICT | Transaction Handle | 2 | 2 |
| 2 | DBDICT | Create Table Record | 32 | 32 |
| 2 | DBDICT | Drop Table Record | 32 | 32 |
| 2 | DBDICT | Alter Table Record | 32 | 32 |
| 2 | DBDICT | Create Index Record | 32 | 32 |
| 2 | DBDICT | Drop Index Record | 32 | 32 |
| 2 | DBDICT | Alter Index Record | 32 | 32 |
| 2 | DBDICT | Build Index Record | 32 | 32 |
| 2 | DBDICT | Create Hash Map Record | 32 | 32 |
| 2 | DBDICT | Copy Data Record | 32 | 32 |
| 2 | DBDICT | Create Trigger Record | 32 | 32 |
| 2 | DBDICT | Drop Trigger Record | 32 | 32 |
| 2 | DBDICT | Create Filegroup Record | 32 | 32 |
| 2 | DBDICT | Create File Record | 32 | 32 |
| 2 | DBDICT | Drop Filegroup Record | 32 | 32 |
| 2 | DBDICT | Drop File Record | 32 | 32 |
| 2 | DBDICT | Operation Record | 0 | 0 |
+---------+--------+-------------------------+-------+------------+
134 rows in set (0.02 sec)
mysql> select * from TABLES;
+----------+-------------------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| TABLE_ID | TABLE_NAME | CREATE_SQL
|
+----------+-------------------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| 0 | TABLES | CREATE TABLE IF NOT EXISTS `NDB$INFO`.`TABLES` (
`TABLE_ID` INT UNSIGNED,
`TABLE_NAME` VARCHAR(512),
`CREATE_SQL` VARCHAR(512)
) ENGINE=NDBCLUSTER_INFO;
|
| 1 | COLUMNS | CREATE TABLE IF NOT EXISTS `NDB$INFO`.`COLUMNS` (
`TABLE_ID` INT UNSIGNED,
`COLUMN_ID` INT UNSIGNED,
`COLUMN_NAME` VARCHAR(512),
`COLUMN_TYPE` VARCHAR(512)
) ENGINE=NDBCLUSTER_INFO;
|
| 2 | MEMUSAGE | CREATE TABLE IF NOT EXISTS `NDB$INFO`.`MEMUSAGE` (
`RESOURCE_NAME` VARCHAR(512),
`NODE_ID` INT UNSIGNED,
`PAGE_SIZE_KB` INT UNSIGNED,
`PAGES_USED` INT UNSIGNED,
`PAGES_TOTAL` INT UNSIGNED,
`BLOCK_NUMBER` INT UNSIGNED
) ENGINE=NDBCLUSTER_INFO;
|
| 3 | LOGDESTINATION | CREATE TABLE IF NOT EXISTS
`NDB$INFO`.`LOGDESTINATION` (
`NODE_ID` INT UNSIGNED,
`TYPE` VARCHAR(512),
`PARAMS` VARCHAR(512),
`CURRENT_SIZE` INT UNSIGNED,
`MAX_SIZE` INT UNSIGNED
) ENGINE=NDBCLUSTER_INFO;
|
| 4 | BACKUP_RECORDS | CREATE TABLE IF NOT EXISTS
`NDB$INFO`.`BACKUP_RECORDS` (
`NODE_ID` INT UNSIGNED,
`BACKUP_RECORD` INT UNSIGNED,
`BACKUP_ID` INT UNSIGNED,
`MASTER_REF` INT UNSIGNED,
`CLIENT_REF` INT UNSIGNED,
`STATE` INT UNSIGNED,
`BYTES` INT UNSIGNED,
`RECORDS` INT UNSIGNED,
`LOG_BYTES` INT UNSIGNED,
`LOG_RECORDS` INT UNSIGNED,
`ERROR_CODE` INT UNSIGNED
) ENGINE=NDBCLUSTER_INFO;
|
| 5 | BACKUP_PARAMETERS | CREATE TABLE IF NOT EXISTS
`NDB$INFO`.`BACKUP_PARAMETERS` (
`NODE_ID` INT UNSIGNED,
`CURRENT_DISK_WRITE_SPEED` INT UNSIGNED,
`BYTES_WRITTEN_THIS_PERIOD` INT UNSIGNED,
`OVERFLOW_DISK_WRITE` INT UNSIGNED,
`RESET_DELAY_USED` INT UNSIGNED,
`RESET_DISK_SPEED_TIME` INT UNSIGNED,
`BACKUP_POOL_SIZE` INT UNSIGNED,
`BACKUP_FILE_POOL_SIZE` INT UNSIGNED,
`TABLE_POOL_SIZE` INT UNSIGNED,
`TRIGGER_POOL_SIZE` INT UNSIGNED,
`FRAGMENT_POOL_SIZE` INT UNSIGNED,
`PAGE_POOL_SIZE` INT UNSIGNED,
`COMPRESSED_BACKUP` |
| 6 | POOLS | CREATE TABLE IF NOT EXISTS `NDB$INFO`.`POOLS` (
`NODE_ID` INT UNSIGNED,
`BLOCK` VARCHAR(512),
`POOL_NAME` VARCHAR(512),
`FREE` INT UNSIGNED,
`SIZE` INT UNSIGNED
) ENGINE=NDBCLUSTER_INFO;
|
+----------+-------------------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
7 rows in set (0.06 sec)
mysql> SELECT * FROM COLUMNS;
+----------+-----------+---------------------------+--------------+
| TABLE_ID | COLUMN_ID | COLUMN_NAME | COLUMN_TYPE |
+----------+-----------+---------------------------+--------------+
| 0 | 0 | TABLE_ID | INT UNSIGNED |
| 0 | 1 | TABLE_NAME | VARCHAR(512) |
| 0 | 2 | CREATE_SQL | VARCHAR(512) |
| 1 | 0 | TABLE_ID | INT UNSIGNED |
| 1 | 1 | COLUMN_ID | INT UNSIGNED |
| 1 | 2 | COLUMN_NAME | VARCHAR(512) |
| 1 | 3 | COLUMN_TYPE | VARCHAR(512) |
| 2 | 0 | RESOURCE_NAME | VARCHAR(512) |
| 2 | 1 | NODE_ID | INT UNSIGNED |
| 2 | 2 | PAGE_SIZE_KB | INT UNSIGNED |
| 2 | 3 | PAGES_USED | INT UNSIGNED |
| 2 | 4 | PAGES_TOTAL | INT UNSIGNED |
| 2 | 5 | BLOCK_NUMBER | INT UNSIGNED |
| 3 | 0 | NODE_ID | INT UNSIGNED |
| 3 | 1 | TYPE | VARCHAR(512) |
| 3 | 2 | PARAMS | VARCHAR(512) |
| 3 | 3 | CURRENT_SIZE | INT UNSIGNED |
| 3 | 4 | MAX_SIZE | INT UNSIGNED |
| 4 | 0 | NODE_ID | INT UNSIGNED |
| 4 | 1 | BACKUP_RECORD | INT UNSIGNED |
| 4 | 2 | BACKUP_ID | INT UNSIGNED |
| 4 | 3 | MASTER_REF | INT UNSIGNED |
| 4 | 4 | CLIENT_REF | INT UNSIGNED |
| 4 | 5 | STATE | INT UNSIGNED |
| 4 | 6 | BYTES | INT UNSIGNED |
| 4 | 7 | RECORDS | INT UNSIGNED |
| 4 | 8 | LOG_BYTES | INT UNSIGNED |
| 4 | 9 | LOG_RECORDS | INT UNSIGNED |
| 4 | 10 | ERROR_CODE | INT UNSIGNED |
| 5 | 0 | NODE_ID | INT UNSIGNED |
| 5 | 1 | CURRENT_DISK_WRITE_SPEED | INT UNSIGNED |
| 5 | 2 | BYTES_WRITTEN_THIS_PERIOD | INT UNSIGNED |
| 5 | 3 | OVERFLOW_DISK_WRITE | INT UNSIGNED |
| 5 | 4 | RESET_DELAY_USED | INT UNSIGNED |
| 5 | 5 | RESET_DISK_SPEED_TIME | INT UNSIGNED |
| 5 | 6 | BACKUP_POOL_SIZE | INT UNSIGNED |
| 5 | 7 | BACKUP_FILE_POOL_SIZE | INT UNSIGNED |
| 5 | 8 | TABLE_POOL_SIZE | INT UNSIGNED |
| 5 | 9 | TRIGGER_POOL_SIZE | INT UNSIGNED |
| 5 | 10 | FRAGMENT_POOL_SIZE | INT UNSIGNED |
| 5 | 11 | PAGE_POOL_SIZE | INT UNSIGNED |
| 5 | 12 | COMPRESSED_BACKUP | INT UNSIGNED |
| 5 | 13 | COMPRESSED_LCP | INT UNSIGNED |
| 6 | 0 | NODE_ID | INT UNSIGNED |
| 6 | 1 | BLOCK | VARCHAR(512) |
| 6 | 2 | POOL_NAME | VARCHAR(512) |
| 6 | 3 | FREE | INT UNSIGNED |
| 6 | 4 | SIZE | INT UNSIGNED |
+----------+-----------+---------------------------+--------------+
48 rows in set (0.57 sec)
mysql>
Example: NDB$INFO_RESOURCES
CREATE TABLE NDB$INFO_RESOURCES (
RESOURCE_NAME VARCHAR(50),
RESOURCE_ID INT,
NODE_ID INT,
RESOURCE_USED INT,
RESOURCE_MAX INT,
PRIMARY KEY (RESOURCE_ID,NODE_ID)
);
mysql> select * FROM NDB$INFO_RESOURCES;
+----------------+-------------+---------+---------------+--------------+
| RESOURCE_NAME | RESOURCE_ID | NODE_ID | RESOURCE_USED | RESOURCE_MAX |
+----------------+-------------+---------+---------------+--------------+
| NoOfTables | 102 | 1 | 20 | 100 |
| NoOfTables | 102 | 2 | 20 | 100 |
| NoOfAttributes | 103 | 1 | 200 | 512 |
| NoOfAttributes | 103 | 2 | 200 | 512 |
+----------------+-------------+---------+---------------+--------------+
4 rows in set (0.00 sec)
For example, upgrading DataMemory where node 2 has been restarted to have
more data memory but node 1 hasn't:
mysql> select * FROM NDB$INFO_RESOURCES WHERE RESOURCE_NAME='DataMemory';
+---------------+-------------+---------+---------------+--------------+
| RESOURCE_NAME | RESOURCE_ID | NODE_ID | RESOURCE_USED | RESOURCE_MAX |
+---------------+-------------+---------+---------------+--------------+
| DataMemory | 112 | 1 | 100 | 288 |
| DataMemory | 112 | 2 | 100 | 512 |
+---------------+-------------+---------+---------------+--------------+
2 rows in set (0.05 sec)
Common
------
Specifying a NDB$INFO table:
Want to be able to do something easy like:
DECLARE_NDBINFO_TABLE(t1,4) = {{"t1",4,0},
{
{"col1",NDBINFO_TYPE_STRING},
{"col2",NDBINFO_TYPE_STRING},
{"col3",NDBINFO_TYPE_STRING},
{"col4",NDBINFO_TYPE_STRING}
}};
for t1 being:
CREATE TABLE `t1` (
`col1` VARCHAR(255),
`col2` VARCHAR(255),
`col3` VARCHAR(255),
`col4` VARCHAR(255)
) ENGINE=NDBINFO;
(we replace STRING with something the SQL server currently understands... with
the cunning plan of introducing STRING at some point).
DBINFO Block
------------
"Manages" everything. Implements some infrastructure. Individual blocks
implement their own tables.
Getting table list:
scan special table (id=0). This table has a list of tables.
Getting column list:
scan special table (id=1). This table has list of all columns.
(In scan interface we could optimise with start/stop block/item id to only
get column info on one table)
Scanning NDB$INFO Tables:
NDBINFO_SCANREQ
tableId // DBINFO table ID
startBlockId // Normally these 4 set to 0 by API
startItemId // but can be used as rather primitive
stopBlockId // pushed down conditions. e.g. to only get
stopItemId // columns of one NDB$INFO TABLE
apiNodeId // API doing scan
apiTxnId // ID unique to API.
column bitmap // bitmap of what columns you want. (64bit)
execNDBINFO_SCANCONF
blockId // to be sent in next NDBINFO_SCANREQ
itemId // as above
When complete, blockid=0xFFFFFFFF (done).
If blockId!=0xFFFFFFFF, API needs to send DBINFO_SCANREQ again
with blockid and item ID we sent them in DBINFO_SCANCONF
BLOCKS Implementing NDB$INFO tables
-----------------------------------
receive NDBINFO_SCANREQ (from DBINFO), send NDBINFO_SCANCONF (to DBINFO) on
completion of scanning some part of the table. sends TRANSID_AI directly to API
for each row.
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