mnesia_frag ????
Sanjaya Vitharana
sanjaya@REDACTED
Mon Jan 16 13:32:23 CET 2006
Hi .. !!!
Can any one show me where I'm doing wrong, I'm trying to write a single record & retrive it using mnesia_frag.
But it's not working :( for me.
(vmdb@REDACTED)29> mnesia:table_info(profile_db, frag_properties).
[{base_table,profile_db},
{foreign_key,undefined},
{hash_module,mnesia_frag_hash},
{hash_state,{hash_state,30,15,4}},
{n_fragments,30},
{node_pool,[vmdb@REDACTED]}]
(vmdb@REDACTED)31> WriteFun1 = fun(DbFile, Rec) -> mnesia:write(DbFile, Rec, write)end.
#Fun<erl_eval.12.2225172>
(vmdb@REDACTED)32> mnesia:activity(transaction, WriteFun1, [profile_db, {profile_db,777,"test",333,1234,5678,1234}], mnesia_frag).
ok --- Here it shows as it works
(vmdb@REDACTED)33> ReadFun = fun(Db,DBKey) -> mnesia:dirty_read(Db, DBKey)end.
#Fun<erl_eval.12.2225172>
(vmdb@REDACTED)34> mnesia:activity(transaction, ReadFun, [profile_db,777], mnesia_frag).
[] -- but empty list given when try to retrive
(vmdb@REDACTED)35> mnesia:dirty_first(profile_db).
'$end_of_table' --- since the db should contains only 2 records, I tried this. but :(
(vmdb@REDACTED)36>
Furthermore I have used below, to create the DB.
-record(profile_db, {mobile_no, prof_details, type, last_update_date, first_creation_date, fax_no}).
Res = mnesia:create_table(profile_db,[
{disc_copies, NodeList},
{type, ordered_set},
{index, [type, last_update_date, first_creation_date, fax_no]},
{frag_properties, [{n_fragments, 30}]},
{attributes, record_info(fields, profile_db)}
]),
----------------------------------------------------------------------------------------------------------------------------------------------------
consider the mnesia:info() result below, and note that the
profile_db_frag2: with 1 records occupying 95 words of mem
disc_copies = [schema]
but I have used {disc_copies, NodeList}
----------------------------------------------------------------------------------------------------------------------------------------------------
(vmdb@REDACTED)43> mnesia:info().
---> Processes holding locks <---
---> Processes waiting for locks <---
---> Participant transactions <---
---> Coordinator transactions <---
---> Uncertain transactions <---
---> Active tables <---
profile_db : with 0 records occupying 70 words of mem
profile_db_frag2: with 1 records occupying 95 words of mem
......
profile_db_frag13: with 1 records occupying 95 words of mem
.......
profile_db_frag29: with 0 records occupying 70 words of mem
profile_db_frag30: with 0 records occupying 70 words of mem
schema : with 31 records occupying 4380 words of mem
===> System info in version "4.2.3", debug level = none <===
opt_disc. Directory "/usr2/omni_vm_prof/db/vmdb" is used.
use fallback at restart = false
running db nodes = [vmdb@REDACTED]
stopped db nodes = []
master node tables = []
remote = []
ram_copies = [profile_db,
profile_db_frag10,
profile_db_frag11,
...
profile_db_frag8,
profile_db_frag9]
disc_copies = [schema]
disc_only_copies = []
[{vmdb@REDACTED,disc_copies}] = [schema]
[{vmdb@REDACTED,ram_copies}] = [profile_db_frag30,
profile_db_frag29,
.....
profile_db_frag3,
profile_db_frag2,
profile_db]
12 transactions committed, 5 aborted, 0 restarted, 0 logged to disc
0 held locks, 0 in queue; 0 local transactions, 0 remote
0 transactions waits for other nodes: []
ok
(vmdb@REDACTED)44>
I have confused with the results, can anyone explane this ??
Thanks in advance.
Sanjaya Vitharana
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