create table "sysmaster".syschfree {显示块中的未用空间块}
(
chknum integer, { chunk number 块号 }
extnum integer, { extent number in chunk 块区域号 }
start integer, { physical addr of start 开始物理地址 }
leng integer { length of extent 区域长度 }
);
create unique index syschfreeidx on syschfree (chknum, extnum);
revoke all on syschfree from public;
grant select on syschfree to public;