syschunks

The syschunks table contains a description of each of the chunks that the database server manages.

In the flags and mflags columns, each bit position represents a separate flag. Thus, it might be easier to read values in the flags and mflags columns if the values are returned by the HEX function.
Table 1. The syschunks table
Column Type Description
chknum smallint Chunk number
dbsnum smallint Dbspace number
nxchknum smallint Number of the next chunk in this dbspace
chksize integer Number of pages in this chunk (in units of system default page size)
offset integer Page offset of the chunk in its device or path
pagesize integer Page size (in bytes)
nfree integer Number of free pages in the chunk

The amount of free space depends on the type of space:

  • dbspace = multiply the number of free pages by the system default page size of either 2 KB or 4 KB.
  • blobspace = multiply the number of free pages by the blobpage size.
  • sbspace = multiply the number of free pages by the sbpage size (which is the same as the system default page size).
is_offline integer 1 = chunk is offline

0 = chunk is online
is_recovering integer 1 = the chunk is being recovered

0 = the chunk is not being recovered
is_blobchunk integer 1 = the chunk is in a blobspace

0 = the chunk is not in a blobspace
is_sbchunk integer 1 = the chunk is an sbspace

0 = the chunk is not in an sbspace
is_inconsistent integer 1 = the chunk is undergoing logical restore

0 = the chunk is not being restored
is_extendable integer 1 = the chunk is extendable

0 = the chunk is not extendable
flags smallint The flags have the following numeric and hexadecimal values and meanings:
  • 16 (0x0010) = Chunk is a mirrored chunk
  • 32 (0x0020) = Chunk is in offline mode
  • 64 (0x0040) = Chunk is in online mode
  • 128 (0x0080) = Chunk is in recovery mode
  • 256 (0x0100) = Chunk is mirrored
  • 512 (0x0200) = Chunk is part of a blobspace
  • 1024 (0x0400) = Chunk is being dropped
  • 2048 (0x0800) = Chunk is part of an optical stageblob
  • 4096 (0x1000) = Chunk is inconsistent
  • 8192 (0x2000) = Chunk is extendable
  • 16384 (0x4000) = Chunk was added during roll forward
  • 32768 (0x8000) = Chunk was renamed
  • 65536 (0x10000) = Chunk uses big chunk page header
  • 131072 (0x20000) = Chunk has a tblspace tblspace extent
  • 262144 (0x40000) = No checkpoint was completed since this chunk was initialized (primarily for internal use)
fname char(256) Path name for the file or device of this chunk
mdsize integer Size in pages of the metadata area of a chunk that belongs to an sbspace.

-1 = the chunk does not belong to an sbspace.
mfname char(256) Path name for the file or device of the mirrored chunk, if any
moffset integer Page offset of the mirrored chunk
mis_offline integer 1 = mirror is offline

0 = mirror is online
mis_recovering integer 1 = mirror is being recovered

0 = mirror is not being recovered
mflags smallint Mirrored chunk flags; values and meanings are the same as the flags column.
udfree integer Free space in pages within the user data area of a chunk that belongs to an sbspace.

-1 = the chunk does not belong to an sbspace.
udsize integer Size in pages of the user data area of a chunk that belongs to an sbspace.

-1 = the chunk does not belong to an sbspace.