Ah, this tool seems very handy. For those curious, I'll paste the results
below. The index approximately doubles the storage size, but I am
intentionally making that tradeoff to avoid the slow down when enforcing a
unique/primary key on the Reference table while inserting.
-AJ
/** Disk-Space Utilization Report For F:/mytestdb2.db
Page size in bytes................................ 4096
Pages in the whole file (measured)................ 104071490
Pages in the whole file (calculated).............. 104071489
Pages that store data............................. 104071489 100.000%
Pages on the freelist (per header)................ 0 0.0%
Pages on the freelist (calculated)................ 1 0.0%
Pages of auto-vacuum overhead..................... 0 0.0%
Number of tables in the database.................. 3
Number of indices................................. 1
Number of defined indices......................... 1
Number of implied indices......................... 0
Size of the file in bytes......................... 426276823040
Bytes of user payload stored...................... 174138410641 40.9%
*** Page counts for all tables with their indices
*****************************
REFERENCE......................................... 93008188 89.4%
MAINDATA.......................................... 11063300 10.6%
SQLITE_MASTER..................................... 1 0.0%
*** Page counts for all tables and indices separately
*************************
REFERENCE......................................... 50304534 48.3%
HASHINDEX......................................... 42703654 41.0%
MAINDATA.......................................... 11063300 10.6%
SQLITE_MASTER..................................... 1 0.0%
*** All tables and indices
****************************************************
Percentage of total database...................... 100.000%
Number of entries................................. 17948049998
Bytes of storage consumed......................... 426276818944
Bytes of payload.................................. 321412979244 75.4%
Bytes of metadata................................. 100378462716 23.5%
Average payload per entry......................... 17.91
Average unused bytes per entry.................... 0.25
Average metadata per entry........................ 5.59
Average fanout.................................... 241.00
Maximum payload per entry......................... 37003
Entries that use overflow......................... 53547 0.0%
Index pages used.................................. 430147
Primary pages used................................ 103581347
Overflow pages used............................... 59995
Total pages used.................................. 104071489
Unused bytes on index pages....................... 96815925 5.5%
Unused bytes on primary pages..................... 4383344069 1.0%
Unused bytes on overflow pages.................... 5242782 2.1%
Unused bytes on all pages......................... 4485402776 1.1%
*** All tables
****************************************************************
Percentage of total database...................... 59.0%
Number of entries................................. 9031683455
Bytes of storage consumed......................... 251362652160
Bytes of payload.................................. 174138410911 69.3%
Bytes of metadata................................. 73116919243 29.1%
Average payload per entry......................... 19.28
Average unused bytes per entry.................... 0.45
Average metadata per entry........................ 8.10
Average fanout.................................... 332.00
Maximum payload per entry......................... 37003
Entries that use overflow......................... 53547 0.0%
Index pages used.................................. 184608
Primary pages used................................ 61123232
Overflow pages used............................... 59995
Total pages used.................................. 61367835
Unused bytes on index pages....................... 94142971 12.5%
Unused bytes on primary pages..................... 4007962045 1.6%
Unused bytes on overflow pages.................... 5242782 2.1%
Unused bytes on all pages......................... 4107347798 1.6%
*** All indices
***************************************************************
Percentage of total database...................... 41.0%
Number of entries................................. 8916366543
Bytes of storage consumed......................... 174914166784
Bytes of payload.................................. 147274568333 84.2%
Bytes of metadata................................. 27261543473 15.6%
B-tree depth...................................... 5
Average payload per entry......................... 16.52
Average unused bytes per entry.................... 0.04
Average metadata per entry........................ 3.06
Average fanout.................................... 173.00
Maximum payload per entry......................... 17
Entries that use overflow......................... 0 0.0%
Index pages used.................................. 245539
Primary pages used................................ 42458115
Overflow pages used............................... 0
Total pages used.................................. 42703654
Unused bytes on index pages....................... 2672954 0.27%
Unused bytes on primary pages..................... 375382024 0.22%
Unused bytes on overflow pages.................... 0
Unused bytes on all pages......................... 378054978 0.22%
*** Table MAINDATA
************************************************************
Percentage of total database...................... 10.6%
Number of entries................................. 115316909
Bytes of storage consumed......................... 45315276800
Bytes of payload.................................. 41033664786 90.6%
Bytes of metadata................................. 1103219478 2.4%
B-tree depth...................................... 4
Average payload per entry......................... 355.83
Average unused bytes per entry.................... 27.56
Average metadata per entry........................ 9.57
Average fanout.................................... 358.00
Non-sequential pages.............................. 10954556 99.02%
Maximum payload per entry......................... 37003
Entries that use overflow......................... 53547 0.046%
Index pages used.................................. 30681
Primary pages used................................ 10972624
Overflow pages used............................... 59995
Total pages used.................................. 11063300
Unused bytes on index pages....................... 15769540 12.5%
Unused bytes on primary pages..................... 3157406006 7.0%
Unused bytes on overflow pages.................... 5242782 2.1%
Unused bytes on all pages......................... 3178418328 7.0%
*** Table REFERENCE and all its indices
***************************************
Percentage of total database...................... 89.4%
Number of entries................................. 17832733086
Bytes of storage consumed......................... 380961538048
Bytes of payload.................................. 280379314188 73.6%
Bytes of metadata................................. 99275243118 26.1%
Average payload per entry......................... 15.72
Average unused bytes per entry.................... 0.07
Average metadata per entry........................ 5.57
Average fanout.................................... 232.00
Maximum payload per entry......................... 17
Entries that use overflow......................... 0 0.0%
Index pages used.................................. 399466
Primary pages used................................ 92608722
Overflow pages used............................... 0
Total pages used.................................. 93008188
Unused bytes on index pages....................... 81046385 5.0%
Unused bytes on primary pages..................... 1225934357 0.32%
Unused bytes on overflow pages.................... 0
Unused bytes on all pages......................... 1306980742 0.34%
*** Table REFERENCE w/o any indices
*******************************************
Percentage of total database...................... 48.3%
Number of entries................................. 8916366543
Bytes of storage consumed......................... 206047371264
Bytes of payload.................................. 133104745855 64.6%
Bytes of metadata................................. 72013699645 35.0%
B-tree depth...................................... 5
Average payload per entry......................... 14.93
Average unused bytes per entry.................... 0.10
Average metadata per entry........................ 8.08
Average fanout.................................... 326.00
Non-sequential pages.............................. 11004959 21.9%
Maximum payload per entry......................... 15
Entries that use overflow......................... 0 0.0%
Index pages used.................................. 153927
Primary pages used................................ 50150607
Overflow pages used............................... 0
Total pages used.................................. 50304534
Unused bytes on index pages....................... 78373431 12.4%
Unused bytes on primary pages..................... 850552333 0.41%
Unused bytes on overflow pages.................... 0
Unused bytes on all pages......................... 928925764 0.45%
*** Index HASHINDEX of table REFERENCE
****************************************
Percentage of total database...................... 41.0%
Number of entries................................. 8916366543
Bytes of storage consumed......................... 174914166784
Bytes of payload.................................. 147274568333 84.2%
Bytes of metadata................................. 27261543473 15.6%
B-tree depth...................................... 5
Average payload per entry......................... 16.52
Average unused bytes per entry.................... 0.04
Average metadata per entry........................ 3.06
Average fanout.................................... 173.00
Non-sequential pages.............................. 0 0.0%
Maximum payload per entry......................... 17
Entries that use overflow......................... 0 0.0%
Index pages used.................................. 245539
Primary pages used................................ 42458115
Overflow pages used............................... 0
Total pages used.................................. 42703654
Unused bytes on index pages....................... 2672954 0.27%
Unused bytes on primary pages..................... 375382024 0.22%
Unused bytes on overflow pages.................... 0
Unused bytes on all pages......................... 378054978 0.22%
*** Table SQLITE_MASTER
*******************************************************
Percentage of total database...................... 0.0%
Number of entries................................. 3
Bytes of storage consumed......................... 4096
Bytes of payload.................................. 270 6.6%
Bytes of metadata................................. 120 2.9%
B-tree depth...................................... 1
Average payload per entry......................... 90.00
Average unused bytes per entry.................... 1235.33
Average metadata per entry........................ 40.00
Maximum payload per entry......................... 94
Entries that use overflow......................... 0 0.0%
Primary pages used................................ 1
Overflow pages used............................... 0
Total pages used.................................. 1
Unused bytes on primary pages..................... 3706 90.5%
Unused bytes on overflow pages.................... 0
Unused bytes on all pages......................... 3706 90.5%
*** Definitions
***************************************************************
Page size in bytes
The number of bytes in a single page of the database file.
Usually 1024.
Number of pages in the whole file
The number of 4096-byte pages that go into forming the complete
database
Pages that store data
The number of pages that store data, either as primary B*Tree pages or
as overflow pages. The number at the right is the data pages divided by
the total number of pages in the file.
Pages on the freelist
The number of pages that are not currently in use but are reserved for
future use. The percentage at the right is the number of freelist pages
divided by the total number of pages in the file.
Pages of auto-vacuum overhead
The number of pages that store data used by the database to facilitate
auto-vacuum. This is zero for databases that do not support auto-vacuum.
Number of tables in the database
The number of tables in the database, including the SQLITE_MASTER table
used to store schema information.
Number of indices
The total number of indices in the database.
Number of defined indices
The number of indices created using an explicit CREATE INDEX statement.
Number of implied indices
The number of indices used to implement PRIMARY KEY or UNIQUE
constraints
on tables.
Size of the file in bytes
The total amount of disk space used by the entire database files.
Bytes of user payload stored
The total number of bytes of user payload stored in the database. The
schema information in the SQLITE_MASTER table is not counted when
computing this number. The percentage at the right shows the payload
divided by the total file size.
Percentage of total database
The amount of the complete database file that is devoted to storing
information described by this category.
Number of entries
The total number of B-Tree key/value pairs stored under this category.
Bytes of storage consumed
The total amount of disk space required to store all B-Tree entries
under this category. The is the total number of pages used times
the pages size.
Bytes of payload
The amount of payload stored under this category. Payload is the data
part of table entries and the key part of index entries. The percentage
at the right is the bytes of payload divided by the bytes of storage
consumed.
Bytes of metadata
The amount of formatting and structural information stored in the
table or index. Metadata includes the btree page header, the cell
pointer
array, the size field for each cell, the left child pointer or non-leaf
cells, the overflow pointers for overflow cells, and the rowid value for
rowid table cells. In other words, metadata is everything that is
neither
unused space nor content. The record header in the payload is counted
as
content, not metadata.
Average payload per entry
The average amount of payload on each entry. This is just the bytes of
payload divided by the number of entries.
Average unused bytes per entry
The average amount of free space remaining on all pages under this
category on a per-entry basis. This is the number of unused bytes on
all pages divided by the number of entries.
Non-sequential pages
The number of pages in the table or index that are out of sequence.
Many filesystems are optimized for sequential file access so a small
number of non-sequential pages might result in faster queries,
especially for larger database files that do not fit in the disk cache.
Note that after running VACUUM, the root page of each table or index is
at the beginning of the database file and all other pages are in a
separate part of the database file, resulting in a single non-
sequential page.
Maximum payload per entry
The largest payload size of any entry.
Entries that use overflow
The number of entries that user one or more overflow pages.
Total pages used
This is the number of pages used to hold all information in the current
category. This is the sum of index, primary, and overflow pages.
Index pages used
This is the number of pages in a table B-tree that hold only key (rowid)
information and no data.
Primary pages used
This is the number of B-tree pages that hold both key and data.
Overflow pages used
The total number of overflow pages used for this category.
Unused bytes on index pages
The total number of bytes of unused space on all index pages. The
percentage at the right is the number of unused bytes divided by the
total number of bytes on index pages.
Unused bytes on primary pages
The total number of bytes of unused space on all primary pages. The
percentage at the right is the number of unused bytes divided by the
total number of bytes on primary pages.
Unused bytes on overflow pages
The total number of bytes of unused space on all overflow pages. The
percentage at the right is the number of unused bytes divided by the
total number of bytes on overflow pages.
Unused bytes on all pages
The total number of bytes of unused space on all primary and overflow
pages. The percentage at the right is the number of unused bytes
divided by the total number of bytes.
*******************************************************************************
The entire text of this report can be sourced into any SQL database
engine for further analysis. All of the text above is an SQL comment.
The data used to generate this report follows:
*/
BEGIN;
CREATE TABLE space_used(
name clob, -- Name of a table or index in the database file
tblname clob, -- Name of associated table
is_index boolean, -- TRUE if it is an index, false for a table
is_without_rowid boolean, -- TRUE if WITHOUT ROWID table
nentry int, -- Number of entries in the BTree
leaf_entries int, -- Number of leaf entries
depth int, -- Depth of the b-tree
payload int, -- Total amount of data stored in this table or index
ovfl_payload int, -- Total amount of data stored on overflow pages
ovfl_cnt int, -- Number of entries that use overflow
mx_payload int, -- Maximum payload size
int_pages int, -- Number of interior pages used
leaf_pages int, -- Number of leaf pages used
ovfl_pages int, -- Number of overflow pages used
int_unused int, -- Number of unused bytes on interior pages
leaf_unused int, -- Number of unused bytes on primary pages
ovfl_unused int, -- Number of unused bytes on overflow pages
gap_cnt int, -- Number of gaps in the page layout
compressed_size int -- Total bytes stored on disk
);
INSERT INTO space_used
VALUES('sqlite_master','sqlite_master',0,0,3,3,1,270,0,0,94,0,1,0,0,3706,0,0,4096);
INSERT INTO space_used VALUES
('MainData','MainData',0,0,126289532,115316909,4,41033664786,240256758,53547,37003,30681,10972624,59995,15769540,3157406006,
5242782,10954556,45315276800);
INSERT INTO space_used VALUES
('Reference','Reference',0,0,8966517149,8916366543,5,133104745855,0,0,15,153927,50150607,0,78373431,850552333,0,11004959,206
047371264);
INSERT INTO space_used VALUES
('HashIndex','Reference',1,0,8916366543,8873908429,5,147274568333,0,0,17,245539,42458115,0,2672954,375382024,0,0,17491416678
4);
COMMIT;
--
Sent from: http://sqlite.1065341.n5.nabble.com/
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