The following sample uses a text file to store rules that are applied to a second text file. The database details you can probably sort out for yourself - the technique maps easily.

use strict;
use warnings;

# First generate a sample data file
open (outFile, '>', "delme.txt") or die "Can't create test file: $!";
print outFile <<DATA;
Server: win1  ID: D: Space: 6496911360
Server: ux22  ID: D: Space: 7973826560
Server: del2  ID: U: Space: 7973228544
Server: del3  ID: U: Space: 3973228544
DATA
close outFile;

# Now a file of match patterns
open (outFile, '>', "delme.regex") or die "Can't create test file: $!"
+;
print outFile <<DATA;
Space:(\b3\\d+)
ServerD:Server: (?i:d)
ID:ID: (\\w+)
DATA
close outFile;

#Now the solution code
my %matchPatterns;
my $matchType = shift;

#Build the pattern table
open inFile, '<', "delme.regex";
while (<inFile>) {
  chomp;
  $matchPatterns{$1} = $2 if /(\w+):(.*)/;
}
close inFile;

if (! defined $matchType) {
  print "Match type must be one of:\n", join ' ', sort keys %matchPatt
+erns;
  exit -1;
}

#Scan the text file
open inFile, '<', 'delme.txt';
while (<inFile>) {
  chomp;
  print "$_\n" if /$matchPatterns{$matchType}/;
}
close inFile;
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With ServerD passed on the command line prints:

Server: del2  ID: U: Space: 7973228544
Server: del3  ID: U: Space: 3973228544
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# This could be loaded from a file, a db, whatever.
$uncompiled_regexp = 'a.*b';
$text =~ /$uncompiled_regexp/;

# If you plan on using the regexp many times, compile it!
$compiled_regexp = qr/$uncompiled_regexp/;
$text =~ $compiled_regexp;
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I like to omit the // for compiled regexp and leave them in for uncompiled regexps, but they are allowed and optional in both cases.

I tried to imagine what you wanted to do and came up with several alternatives but couldn't guess what you really wanted. There's lots of things that are possible. Sure, you can store regular expressions in a database, fetch them, and then apply them to stuff. Now show what you'd like to be doing. Just applying a regex isn't very useful without something else to use the result of that.