[SYMBOL][A][B][C][D][E][F][G][H][I][J][K][L][M][N][O][P][Q][R][S][T][U][V][W][X][Y][Z]o type specifier object data type objectscreating 2nd 3rd constructors instance of 2nd methods 2nd 3rd 4th 5th 6th properties 2nd 3rd 4th 5th declaring inheritance 2nd 3rd 4th 5th 6th OCTET LENGTH() function One to many mappingDNS (domain name server)virtual hosting One to one mappingDNS (domain name server)virtual hosting one-to-many relationships 2nd one-to-one relationships 2nd opendir() function openingdirectories files 2nd 3rd openssl command-line tool (certificates) OpenSSL library installingUNIX Windows 2nd installing (SSL installations) operandscombined with operators defined operating systemsMySQL optimization tips operating systems (OS)scalability 2nd operators addition (+) arithmetic operators 2nd assignment (=) 2nd 3rd combined assignment operators 2nd 3rd 4th comparison comparison operators 2nd concatentation (.) 2nd defined 2nd logical 2nd 3rd operands combined with post-decrement 2nd 3rd 4th post-increment 2nd 3rd 4th precedence 2nd 3rd 4th operators. [See also expressions]OPTIMIZE TABLE command 2nd 3rd optional argumentsexample 2nd 3rd optionsapache.exeserver binary (Windows) Optionsdirective value optionshttpdserver binary (Unix) Options directiveparameters Options directive (mass virtual hosting) or operator (||) 2nd ORDER BY clause 2nd 3rd Order directivecontrol access rulesevaluating Order directivesAllow, Deny argument Deny, Allow argument Mutual-Failure argument OS (operating systems)scalability 2nd output() function 2nd overrideschemasdirectives ownershipverifying