Building OpenLDAP from sources and missing BerkelyDB

Seems you are using tarball installation, first you should install Berkeley DB. You can find it from oracle website at Oracle Berkeley DB Downloads. Compile and install it.

cd db-4.7.25.NC
. ./dist/configure
make
make install
cd /usr/local/BerkeleyDB.4.7/

This will install BerkeleyDB. Now you need to provide the location to successfully compile OpenLDAP.

export CPPFLAGS="-I/usr/local/BerkeleyDB.4.7/include"
export LDFLAGS="-L/usr/local/BerkeleyDB.4.7/lib -Wl,-R,/usr/local/BerkeleyDB.4.7/lib -Wl,--enable-new-dtags"
# Build OpenLDAP
... 

If you don't set RPATH then you should add LD_LIBRARY_PATH to /etc/profile.

export LD_LIBRARY_PATH="/usr/local/BerkeleyDB.4.7/lib"

After this compile OpenLDAP, let me know if you face any issue.

do yum install db4-devel

(or just install the prepackaged openldap, yum install openldap-servers openldap-clients