Relation 0 does not exist

Hi.

When I run SQL command, I've got the error messe 'Relation 0 doesn't exist'
and following log messages were generated.
After this error happens, I can not access database at all.

Could you kindly advise why this kind of error happens?

Regards,
y.furuse

----------------------------------------------------------------------------
---------------------------------------------------------------
[Version]
PosrgreSQL7.2.4

[SQL command]
INSERT INTO SDBA2 SELECT * FROM VHIST2 ;

[TABLE Layout]
CREATE TABLE SDBA2(
Client TEXT,
RESVNO TEXT,
DEPT TEXT,
CUSTID TEXT,
DT DATE,
TM INT,
DTM TEXT,
RESVTM TIMESTAMP,
CPLTTM TIMESTAMP,
WTM INTERVAL,
STM INTERVAL,
OBJ TEXT,
METHOD TEXT,
COMTM TEXT,
DIAG TEXT,
TREAT TEXT,
NEXT TEXT,
AG TEXT,
AGDAYS INT,
AGDT DATE,
FU TEXT,
FUDAYS INT,
FUDT DATE,
PS TEXT,
PSDAYS INT,
PSDT DATE,
STS TEXT,
COMMNT TEXT,
AGE INT,
SEX TEXT,
OCCUP TEXT,
ITYP TEXT,
ATT1 TEXT,
PRIMARY KEY(CLIENT,RESVNO)
);

[LOG message]
Feb 25 02:30:01 postgres[736]: [1] DEBUG: server process (pid 32278) was
terminated by signal 11
Feb 25 02:30:01 postgres[736]: [2] DEBUG: terminating any other active
server processes
Feb 25 02:30:01 postgres[736]: [3] DEBUG: all server processes terminated;
reinitializing shared memory and semaphores
Feb 25 02:30:01 postgres[32289]: [4] DEBUG: database system was
interrupted at 2006-02-25 01:52:52 JST
Feb 25 02:30:01 postgres[32289]: [5] DEBUG: checkpoint record is at
1/1DE7CE8C
Feb 25 02:30:01 postgres[32289]: [6] DEBUG: redo record is at 1/1DE7CE8C;
undo record is at 0/0; shutdown FALSE
Feb 25 02:30:01 postgres[32289]: [7] DEBUG: next transaction id: 6670787;
next oid: 117726
Feb 25 02:30:01 postgres[32289]: [8] DEBUG: database system was not
properly shut down; automatic recovery in progress
Feb 25 02:30:01 postgres[32289]: [9] DEBUG: ReadRecord: record with zero
length at 1/1DE7CECC
Feb 25 02:30:01 postgres[32289]: [10] DEBUG: redo is not required
Feb 25 02:30:11 postgres[32289]: [11] DEBUG: database system is ready
Feb 25 03:00:00 postgres[1006]: [4] ERROR: cannot open segment 1 of
relation pg_statistic_relid_att_index (target block 858666545): No such file
or directory
Feb 25 03:30:00 postgres[2452]: [4] ERROR: cannot open segment 1 of
relation pg_statistic_relid_att_index (target block 858666545): No such file
or directory
Feb 25 04:00:00 postgres[3896]: [4] ERROR: cannot open segment 1 of
relation pg_statistic_relid_att_index (target block 858666545): No such file
or directory