On 05/05/2018 12:13 PM, Adrian Klaver wrote:
On
05/05/2018 07:14 AM, Ron wrote:
Hi,
v9.6
We've got big databases where some of the tables are highly
compressible, but some have many bytea fields containing PDF
files.
Can you see a demonstrable difference?
Very much so. The ASCII hex representations of the PDF files are
compressible, but take a long time to compress.
Uncompressed backups are 50% faster.
When the data format is custom, directory or tar, how feasible
would a "--no-blob-compression" option be (where pg_dump just
tells the zlib library to just Store tables with bytea columns,
while compressing all other tables at the specified -Z level)?
In pg_dump blob refers to large objects:
https://www.postgresql.org/docs/10/static/app-pgdump.html
"
-b
--blobs
Include large objects in the dump. This is the default
behavior except when --schema, --table, or --schema-only is
specified. The -b switch is therefore only useful to add large
objects to dumps where a specific schema or table has been
requested. Note that blobs are considered data and therefore will
be included when --data-only is used, but not when --schema-only
is.
"
These are different critters then bytea.
Ok. I need the data in my backups anyway, so excluding them is 100%
contrary to what I need.
--
Angular momentum makes the world go 'round.
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