Re: Sysmaster:sysptnXXX

In article <5vm30f$h65@cssun.mathcs.emory.edu>, Manoj <manoj@mailhost.tw owaytv.co.uk> writes >Does anyone know of how to relate to the sysmaster tables: sysptnXXX, >in particular(sysptnext, sysptnhdr, sysptnkey & sysptntab) > Check $INFORMIXDIR/etc/sysmaster.sql - When online starts with oninit -i it runs this script: dbaccess < $INFORMIXDIR/etc/sysmaster.sql to build the sysmaster database. sysptnext SYStem ParTitioN eXTents pe_partnum is the partition (table) number. run select hex(partnum),tabname from systables and this is the partnum. (Ignore three hex digits - this is the dbspace containing the table. pe_extnum extent number pe_phys physical address for this extent (I assume the physical page number for the start of the extent), First part (12 bits? - can't remember how many bits but limit of 2048 chunks in online suggests 12 bits) is chunk number, rest is the page numberwithin the chunk. pe_size size of the extent (I assume in pages). pe_log logical page number of start i.e. page number within the table of the start of the extext. sysptnhdr is fairly clear, so that is how you get the next serial value for a table!! sysptnkey SYStem ParTitioN KEYs (index keys on the table). This describes the indexes on the table and which columns they are on. rootnode = logical page number within table for the root node of the index. nparts = number of parts (columns) within the index e.g. an index on (col1,col2) has two columns "within" the index. keylen = total size in bytes of the columns within the index kpartno = which column in the index this is e.g. for index on (col1,col2) the partno for the row describing col1 is 1 the partno for the row desribing col2 is 2. kpstart = key part start i.e. for the row describing col1 how many bytes into a row is col1. kpleng = key part length i.e. for the row describing col1 how many bytes wide is the column col1. kptype = key part type i.e. for the row describing col1 what typeis the column col1. sysptntab (open tables in shared memory) this is fairly clear (well part num and the pf_ bits are!). NOTE this is all guesswork based on my knowledge of online terms and the Online Admin Guide Version 7.1 VOlume 2 Page 43-20. Fascinating Chapter. PS You ought to go on the Online Database Administrators Course. fun with hex dumps of disk pages and internals of disk allocation. You will probably need to try doing selects from these tables and compare against the output from oncheck -pe to get extent info. Of course since this is internal it could all change in the next release. >Thanks, > > Manoj Schroff, > Two Way TV Ltd, UK > +44(0)181 996 8221 > manoj@mailhost.twowaytv.co.uk > http://www.twowaytv.co.uk > > -- David Williams