unfortunately yes Thanks to jared's example i have a clearer idea now :)
coz I am a NoviceDBA Oracle Certifiable DBBS ----- Original Message ----- To: "Multiple recipients of list ORACLE-L" <[EMAIL PROTECTED]> Sent: Friday, September 28, 2001 3:00 PM > > Which myth did you have in mind ? > > I hadn't heard any that suggested that PL/SQL > was particularly subtle or memory efficient. > > You're not associating this pl/sql implementation > detail with the fact that a varchar2() column when > stored in a datablock uses only the exact length > required to store the current value, are you ? > > > Jonathan Lewis > http://www.jlcomp.demon.co.uk > > Host to The Co-Operative Oracle Users' FAQ > http://www.jlcomp.demon.co.uk/faq/ind_faq.html > > Author of: > Practical Oracle 8i: Building Efficient Databases > > Screen saver or Life saver: http://www.ud.com > Use spare CPU to assist in cancer research. > > > I was reading the Oracle PL/SQL manual and this is what I found. One > more myth goes down > > The VARCHAR2 datatype involves a trade-off between memory use and > efficiency. For a VARCHAR2(>= 2000) variable, PL/SQL dynamically > allocates only enough memory to hold the actual value. However, for a > VARCHAR2(< 2000) variable, PL/SQL preallocates enough memory to hold a > maximum-size value. So, for example, if you assign the same 500-byte > value to a VARCHAR2(2000) variable and to a VARCHAR2(1999) variable, > the latter uses 1499 bytes more memory. > > > > -- > Please see the official ORACLE-L FAQ: http://www.orafaq.com > -- > Author: Jonathan Lewis > INET: [EMAIL PROTECTED] > > Fat City Network Services -- (858) 538-5051 FAX: (858) 538-5051 > San Diego, California -- Public Internet access / Mailing Lists > -------------------------------------------------------------------- > To REMOVE yourself from this mailing list, send an E-Mail message > to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in > the message BODY, include a line containing: UNSUB ORACLE-L > (or the name of mailing list you want to be removed from). You may > also send the HELP command for other information (like subscribing). > -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: novicedba INET: [EMAIL PROTECTED] Fat City Network Services -- (858) 538-5051 FAX: (858) 538-5051 San Diego, California -- Public Internet access / Mailing Lists -------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).
