Compiling with/without Special Features

There are several FLAGS that enable or disable one or more (special) features. These FLAGS can be found in both Makefiles (Makefile.Linux/Makefile.Windows) and have the following effects.

• -DROLE_REFCOUNT: Use reference counting instead of role (multi-)sets; this implementation is faster, but not suited for debugging purposes, since role IDs are invisible. It is strongly recommended to turn this compile option ON.
• -DNO_OPTIMIZATIONS: Disable (most of the) optimizations; this should be used only for debugging purposes or to get better insights into the engine's internal processing strategy.
• -DREWRITE_VARSTEPS: Rewrite varstep expressions into for-loops. On the one hand this option causes earlier signOff statement execution but on the other hand it (might) interfere with other optimizations and therefore can slow down query evaluation.
• -DVALIDATION: Enable XML document validation; please note that only those parts of the XML document are validated that are kept according to the projection strategy. For the remaining part only depth is kept track of (but closing tags are not matched against opening tags). You should ignore this option if you are sure that your XML documents are well-formed.

By default, both Makefiles (Makefile.Linux/Makefile.Windows) come with

FLAGS = -DROLE_REFCOUNT.

If you want to adjust FLAGS to your own needs this must be done before compilation of the sources.

To change FLAGS you can either uncomment one of the following lines in your Makefile (Makefile.Linux/Makefile.Windows)

# FLAGS = -DROLE_REFCOUNT -DREWRITE_VARSTEPS

# FLAGS = -DROLE_REFCOUNT -DNO_OPTIMIZATIONS

# FLAGS = -DROLE_REFCOUNT -DNO_OPTIMIZATIONS -DREWRITE_VARSTEPS

by removing the # before one of these line or just type your own FLAGS line, for example

FLAGS = -DROLE_REFCOUNT -DVALIDATION

if you want to use role (multi-)sets instead of reference counting and want to ensure that your XML document is well-formed.

After changing FLAGS you need to clean and rebuild GCX by typing

> make -f Makefile.Linux clean all

or

> make -f Makefile.Windows clean all

depending on your operating system.

Warning: Compiling GCX with different FLAGS such as -DVALIDATION for XML document well-formed validation or -DNO_OPTIMIZATIONS to disable (most of the) optimizations might significantly slow down query evaluation and is not a recommended compile option!