dev-db/postgresql/metadata.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE pkgmetadata SYSTEM "http://www.gentoo.org/dtd/metadata.dtd">
<pkgmetadata>
    <maintainer type="project">
        <email>pgsql-bugs@gentoo.org</email>
        <name>PostgreSQL and Related Package Development</name>
    </maintainer>
    <use>
        <flag name="pg_legacytimestamp">
            Use double precision floating-point numbers instead of 64-bit
            integers for timestamp storage.
        </flag>
        <flag name="server">
            Disable to build and install the clients and libraries only.
        </flag>
        <flag name="uuid">
            Enable server side UUID generation (via
            <pkg>dev-libs/ossp-uuid</pkg>).
        </flag>
    </use>
</pkgmetadata>