Monitoring sbspaces with oncheck -pe

The oncheck -pe option displays information that includes the size in pages of the chunk, the number of pages used, the number of pages that are free, and a list of all the tables in the chunk, with the initial page number and the length of the table in pages. This option also shows if smart large objects occupy contiguous space within an sbspace.

Execute oncheck -pe to display the following information to determine if the smart large objects occupy contiguous space within an sbspace:
  • Identifies each smart large object with the term SBLOBSpace LO

    The three values in brackets following SBLOBSpace LO correspond to the Sbs#, Chk#, and Seq# columns in the -cS output.

  • Offset of each smart large object
  • Number of disk pages (not sbpages) used by each smart large object
Tip: The oncheck -pe option provides information about sbspace use in terms of database server pages, not sbpages.
Figure 1 shows sample output. In this example, the size field shows that the first smart large object occupies eight pages. Because the offset field shows that the first smart large object starts at page 53 and the second smart large object starts at page 61, the first smart large object occupies contiguous pages.
Figure 1. oncheck -pe output that shows contiguous space use
Chunk Pathname                                      Size      Used      Free
                                                    1000       940        60

    Description                                          Offset     Size
    -------------------------------------------------- -------- --------
    RESERVED PAGES                                            0        2
    CHUNK FREELIST PAGE                                       2        1
    s9_sbspc:'informix'.TBLSpace                              3       50
    SBLOBSpace LO [2,2,1]                                    53        8
    SBLOBSpace LO [2,2,2]                                    61        1
    SBLOBSpace LO [2,2,3]                                    62        1
    SBLOBSpace LO [2,2,4]                                    63        1
    SBLOBSpace LO [2,2,5]                                    64        1
    SBLOBSpace LO [2,2,6]                                    65        1
...

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