Hello,

I would like to ask the memory usage estimation with the formula, not with the ndb_size.pl script.

The table schema is; CREATE TABLE `t1` ( `id` varchar(32) NOT NULL, `intcol1` int(32) DEFAULT NULL, `intcol2` int(32) DEFAULT NULL, `intcol3` int(32) DEFAULT NULL, `intcol4` int(32) DEFAULT NULL, `intcol5` int(32) DEFAULT NULL, `charcol1` varchar(128) DEFAULT NULL, `charcol2` varchar(128) DEFAULT NULL, `charcol3` varchar(128) DEFAULT NULL, `charcol4` varchar(128) DEFAULT NULL, `charcol5` varchar(128) DEFAULT NULL, PRIMARY KEY (`id`)

The number of rows is 10,000.

With VARCHAR, I inserted the max size of data such as ;

I didn't delete the data, and output of all dump 1000 is;

2008-05-07 14:45:43 [MgmSrvr] INFO -- Node 2: Data usage is 6%(166 32K pages of total 2560) 2008-05-07 14:45:43 [MgmSrvr] INFO -- Node 2: Index usage is 1%(28 8K pages of total 2336) 2008-05-07 14:45:43 [MgmSrvr] INFO -- Node 2: Resource 0 min: 0 max: 639 curr: 0 2008-05-07 14:45:43 [MgmSrvr] INFO -- Node 3: Data usage is 6%(166 32K pages of total 2560) 2008-05-07 14:45:43 [MgmSrvr] INFO -- Node 3: Index usage is 1%(28 8K pages of total 2336) 2008-05-07 14:45:43 [MgmSrvr] INFO -- Node 3: Resource 0 min: 0 max: 639 curr: 0 2008-05-07 14:45:43 [MgmSrvr] INFO -- Node 4: Data usage is 6%(178 32K pages of total 2560) 2008-05-07 14:45:43 [MgmSrvr] INFO -- Node 4: Index usage is 1%(31 8K pages of total 2336) 2008-05-07 14:45:43 [MgmSrvr] INFO -- Node 4: Resource 0 min: 0 max: 639 curr: 0 2008-05-07 14:45:43 [MgmSrvr] INFO -- Node 5: Data usage is 6%(178 32K pages of total 2560) 2008-05-07 14:45:43 [MgmSrvr] INFO -- Node 5: Index usage is 1%(31 8K pages of total 2336) 2008-05-07 14:45:43 [MgmSrvr] INFO -- Node 5: Resource 0 min: 0 max: 639 curr: 0

Output of ndb_desc is here;

[root@h1 mysql-cluster]# /usr/local/mysql/bin/ndb_desc -c 192.168.47.128 t1 -d mysqlslap -p -- t1 -- Version: 1 Fragment type: 5 K Value: 6 Min load factor: 78 Max load factor: 80 Temporary table: no Number of attributes: 11 Number of primary keys: 1 Length of frm data: 382 Row Checksum: 1 Row GCI: 1 SingleUserMode: 0 ForceVarPart: 1 TableStatus: Retrieved -- Attributes -- id Varchar(32;latin1_swedish_ci) PRIMARY KEY DISTRIBUTION KEY AT=SHORT_VAR ST=MEMORY intcol1 Int NULL AT=FIXED ST=MEMORY intcol2 Int NULL AT=FIXED ST=MEMORY intcol3 Int NULL AT=FIXED ST=MEMORY intcol4 Int NULL AT=FIXED ST=MEMORY intcol5 Int NULL AT=FIXED ST=MEMORY charcol1 Varchar(128;latin1_swedish_ci) NULL AT=SHORT_VAR ST=MEMORY charcol2 Varchar(128;latin1_swedish_ci) NULL AT=SHORT_VAR ST=MEMORY charcol3 Varchar(128;latin1_swedish_ci) NULL AT=SHORT_VAR ST=MEMORY charcol4 Varchar(128;latin1_swedish_ci) NULL AT=SHORT_VAR ST=MEMORY charcol5 Varchar(128;latin1_swedish_ci) NULL AT=SHORT_VAR ST=MEMORY

-- Indexes -- PRIMARY KEY(id) - UniqueHashIndex PRIMARY(id) - OrderedIndex

-- Per partition info -- Partition Row count Commit count Frag fixed memory Frag varsized memory 0 2515 3107 131072 1966080 2 2572 3084 131072 1966080 1 2507 2891 131072 1966080 3 2406 2918 131072 1966080

NDBT_ProgramExit: 0 - OK

We have four data node, and each two is running on one server. So, there are two servers with RedHat on VMWare.

Now, my calculation is here.

From this page, http://dev.mysql.com/doc/refman/5.1/en/mysql-cluster-ndbd-definition.html

VARCHAR need 8 bytes overhead, so,

INT: 4*5=20 VARCHAR: (12+8)+5*(128+8)=776 Overhead for row: 16 Total 812 byte

FLOOR ((32*1024 - 128) / 812 ) +1 =41 rows per page

10,000 rows / 41 = 244 pages

The result of my calculation is differ from the output of all dump 1000 and ndb_desc command.

Does anyone have any comments on this?

Thanks,