How to enable wirecompression on Firebird 3.0 - delphi

Question

I work with Firebird and Delphi, I want to implement access via internet with wirecompression;
But I am unable to activate it.
I have followed the steps inside this document for the new parameter(one of the few I was able to find)
How to enable WireCompression on Firebird 3.0 using FireDAC
In the tests I use
Windows server 2012 R2
Firebird : Firebird-3.0.4.33054_0_Win32(32 bits)
Also copied to executable folder.
fbclient.dll
zlib1.dll (idem server and client)
created firebird.conf with wirecompression=true.
and I am giving wirecompression=true inside the Firedac of the application.
Why am I unable to activate the P15:CZ compression ?
Sending connection info for the example:
================================
Connection definition parameters
================================
DriverID=FB
Database=miservidor001:C:\sysdat\C100\gestdat03.fdb
User_Name=SYSDBA
PassWord=*****
WireCompression=true
================================
FireDAC info
================================
Tool = RAD Studio 10.2
FireDAC = 16.0.0 (Build 88974)
Platform = Windows 32 bit
Defines = FireDAC_NOLOCALE_META;FireDAC_MONITOR
================================
Client info
================================
Loading driver FB ...
Brand = Firebird
Client version = 300049900
Client DLL name = C:\APPS\WC01\fbclient.dll
================================
Session info
================================
Current catalog =
Current schema =
Server version = WI-V3.0.4.33054 Firebird 3.0
WI-V3.0.4.33054 Firebird 3.0/tcp (WIN-2012LAGO003)/P15:C
WI-V3.0.4.33054 Firebird 3.0/tcp (nucleo)/P15:C'

Answer 1

NOTE: I don't know Delphi nor FireDAC, this answer is based on the general behavior of Firebird and my experience with maintaining its JDBC driver (Jaybird). So it is possible that there is a better answer specifically for FireDAC/Delphi.
Enabling or disabling wire compression is entirely determined by the client, not by the server. This means that configuration of the server is not necessary nor has it any effect, except in cases where the server itself acts as a client, for example with execute statement ... on external datasource.
To be able to use wire compression, you need three things:
fbclient.dll
zlib1.dll (in the same location as fbclient.dll, or on the search path)
A configuration to enable wire compression for the client
Point 3 is likely your problem: I'm not sure if FireDAC has a connection property WireCompression that actually enables wire compression.
I know of two ways to enable wire compression for the client:
Create a firebird.conf in the same directory as the fbclient.dll used by your application. In this configuration file, put the requested configuration options (one per line):
WireCompression = true
# maybe other config lines (eg AuthClient, WireCrypt, etc)
Instead of creating a firebird.conf file, pass the configuration (with linebreaks separating config options) in the isc_dpb_config (int 87) database parameter item.
The value is the same as the content of the firebird.conf file in the previous option. This may run into size issues if the client is using the old database parameter buffer format (where strings are max 255 bytes) and you want to pass (a lot) more config options.
Option 1 is probably the simplest and will work for all frameworks. Option 2 depends on whether or not the framework or driver exposes the database parameter buffer or if it has a connection property that maps to isc_dpb_config.
For example in Java using Jaybird, you can enable compression (only when using native connections) using:
Properties props = new Properties();
props.setProperty("user", "sysdba");
props.setProperty("password", "masterkey");
props.setProperty("config", "WireCompression=true");
try (var connection = DriverManager.getConnection(
"jdbc:firebirdsql:native:localhost:D:/data/db/fb3/fb3testdatabase.fdb", props)) {
FirebirdConnection fbCon = connection.unwrap(FirebirdConnection.class);
FbDatabase fbDatabase = fbCon.getFbDatabase();
System.out.println(fbDatabase.getServerVersion());
} catch (SQLException e) {
e.printStackTrace();
}
This prints out WI-V3.0.4.33054 Firebird 3.0,WI-V3.0.4.33054 Firebird 3.0/tcp (host)/P15:CZ,WI-V3.0.4.33054 Firebird 3.0/tcp (host)/P15:CZ (note this is <server version>,<server protocol info>,<client protocol info>). The Z in P15:CZ means that the connection is zlib compressed (the C that the connection is encrypted).
Here, the config property is an alias for isc_dpb_config.

Answer 2

Mark's answer is the best (and probably the only) source of information about this problem in the entire internet. Good luck finding anything on Delphi, FireDAC or Firebird documentation about what he said.
Based on his answer, here is what you need to use Firebird wire compression with FireDAC:
You need Delphi Rio 10.3.1 (Update 1) or later. Only in this version the config low level parameter (see below) was added to FireDAC.
You must pass WireCompression=true to the low level config connection parameter. This is NOT TFDConnection.Params (high level).
To accomplish this you need to set the IBAdvanced property of TFDPhysFBConnectionDefParams to config=WireCompression=true (yeah! Go figure it!)
Code:
FDConnection1.DriverName := '​FB';
with FDConnection1.Params as TFDPhysFBConnectionDefParams do
begin
Server := '...';
Database := '...';
UserName := '...';
Password := '...';
IBAdvanced := 'config=WireCompression=true';
end;
FDConnection1.Connected := True;
Using a connection definition file:
[FB_Demo]
DriverID=FB
Server=...
Database=...
User_Name=...
Password=...
IBAdvanced=config=WireCompression=true
You need zlib1.dll in the same path of your fbclient.dll. The catch here is that Firebird distribution DOES NOT have the 32-bit version of zlib1.dll in its C:\Program Files\Firebird\Firebird_3_0\WOW64 folder. So:
If your application is 64-bit you are probably fine. Just use both fbclient.dll and zlib1.dll from your C:\Program Files\Firebird\Firebird_3_0 folder.
If your application is 32-bit you have to download the 32-bit version of zlib1.dll from the 32-bit Firebird distribution. Use it together with the fbclient.dll you find in your C:\Program Files\Firebird\Firebird_3_0\WOW64 (which contains 32-bit libraries).
In Firebird 3.0.4 or later you can use the WIRE_COMPRESSED context variable to check if the connection was established as you expected:
SELECT
RDB$GET_CONTEXT('SYSTEM', 'WIRE_COMPRESSED') wire_compressed
FROM
rdb$database
This will return TRUE if the current connection is compressed.