[Firebird-devel] RFC: RDB$BLOB_UTIL system package

[Adriano dos Santos Fernandes]

Hi!

I have created RDB$BLOB_UTIL package pull request:

https://github.com/FirebirdSQL/firebird/pull/281

Here is a test comparing how problematic is the current approach (which
has exponential time complexity and space storage) of creating blobs in
PSQL with the RDB$BLOB_UTIL approach.

Current:

------
Takes 0m12,772s and resulting database has 117334016 size

isql -term !
create database 'b.fdb'!

create table t (b blob sub_type binary)!

execute block
as
    declare b blob;
    declare s varbinary(10000) = '0';
    declare i integer;
begin
    i = 1;
    while (i < 10000)
    do
    begin
        s = s || '0';
        i = i + 1;
    end

    b = s;

    i = 1;
    while (i < 150)
    do
    begin
        b = b || s;
        i = i + 1;
    end

    insert into t (b) values (:b);
end!

commit!
------


RDB$BLOB_UTIL:

------
Takes 0m0,502s and resulting database has 3383296 size.

isql -term ! -ch utf8
create database 'b.fdb'!

create table t (b blob sub_type binary)!

execute block
as
    declare bh integer;
    declare b blob;
    declare s varbinary(10000) = '0';
    declare i integer;
begin
    bh = rdb$blob_util.new(false, false);

    i = 1;
    while (i < 10000)
    do
    begin
        s = s || '0';
        i = i + 1;
    end

    i = 0;
    while (i < 150)
    do
    begin
        execute procedure rdb$blob_util.append(bh, s);
        i = i + 1;
    end

    insert into t (b) values (rdb$blob_util.make_blob(:bh));
end!

commit!
------


Adriano


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