Oracle 5.0 Reference Manual page 1313

Segment information includes these values:
id: The segment ID.
space, page: The tablespace number and page within the tablespace where the segment "inode" is
located. A tablespace number of 0 indicates the shared tablespace.
of segments in the tablespace. The other fields displayed for a segment (id, res, and so forth) are
derived from information in the inode.
res: The number of pages allocated (reserved) for the segment.
used: The number of allocated pages in use by the segment.
ext: The number of extents allocated for the segment that are completely used.
full
pages: The number of initial pages that have been allocated to the segment.
fragm
extents: The number of extents allocated for the segment that are completely unused.
free
not full
pages: The number of pages used within the not-full extents.
When a segment grows, it starts as a single page, and
individually, up to 32 pages (this is the
64-page extents.
sequentiality of data.
For the example segment shown earlier, it has 32 fragment pages, plus 2 full extents (64 pages each),
for a total of 160 pages used out of 160 pages allocated. The following segment has 32 fragment
pages and one partially full extent using 14 pages for a total of 46 pages used out of 96 pages
allocated:
SEGMENT id 0 1 space 0; page 2; res 96 used 46; full ext 0
fragm pages 32; free extents 0; not full extents 1: pages 14
It is possible for a segment that has extents allocated to it to have a
if some of the individual pages have been deallocated subsequent to extent allocation.
14.2.12.2.3.
InnoDB
The
InnoDB
The output contains one section per table. The
for internal data dictionary tables that maintain information about foreign keys. There are also sections
for the Table Monitor table and each user-created
have been created in the
CREATE TABLE parent
(
par_id
fname
lname
PRIMARY KEY (par_id),
UNIQUE INDEX (lname, fname)
) ENGINE = INNODB;
CREATE TABLE child
(
par_id
child_id
name
birth
weight
misc_info
last_update TIMESTAMP,
PRIMARY KEY (par_id, child_id),
Performance Tuning and Troubleshooting
InnoDB
extents: The number of extents allocated for the segment that are partially used.
can add up to 4 extents at a time to a large segment to ensure good
InnoDB
Table Monitor Output
Table Monitor prints the contents of the
database:
test
INT NOT NULL,
CHAR(20),
CHAR(20),
INT NOT NULL,
INT NOT NULL,
VARCHAR(40),
DATE,
DECIMAL(10,2),
VARCHAR(255),
InnoDB
value). After that,
fragm pages
InnoDB
SYS_FOREIGN
table. Suppose that the following two tables
InnoDB
1293
uses inodes to keep track
InnoDB
allocates the first pages for it
allocates complete
InnoDB
value less than 32
fragm pages
internal data dictionary.
and
SYS_FOREIGN_COLS
sections are