sql - Oracle - delete based on join with two other tables -


i'm having little trouble designing code run fast.

my requirments are:

i have table scd(180mil records) , smaller table log(about 300 records).

log structure:

real_key | fic_key

scd structure :

another_key | serial_key ....

i need delete scd real key's, exists record fic_key, like

delete scd t serial_number in(select real_key log l1) , exists(select 1 scd s,log l2 s.serial_key = l2.fic_key            , l2.real_key = l1.real_key)

the problem cant use first correlated query results compare second (l2.real_key = l1.real_key). also, if run, take lot of time since scd contains lot of records.

any appriciated.

first decide keys should deleted.

if want delete onlyreal_keys fic_key exist in scd, follows: 

select real_key  log join scd on log.fic_key = scd.serial_key

the delete than

delete scd serial_key in (  select real_key  log join scd on log.fic_key = scd.serial_key);

if have index on serial_key in scd delete done 2 nl joins should quite instant. if no performance estimated 2 hash joins of scd table small table. should not ages 180m rows. may speed bit using parallel hash join.


Comments

Post a Comment

Popular posts from this blog

Unlimited choices in BASH case statement -

consider simple bash snippet: case $option in 1) image=${options[0]%.tar} ;; 2) image=${options[1]%.tar} ;; 3) image=${options[2]%.tar} ;; 4) image=${options[3]%.tar} ;; *) echo "invalid option" exit 1 esac in real script numbers goes 30. makes pretty long. can somehow specify cases variable? something this: case $option in $i) image=${options[$(($i-1))]%.tar} any pointer appreciated. you can match against multiple patterns in single clause: case $option in 1|2|3: echo "$option one, 2 or three" ;; esac if still typing you, can use simple pattern matching: case $option in # following matches # - single-digit numbers 0-9 # - two-digit numbers starting either 1 or 2 # - number 30 [0-9]|[12][0-9]|30) image=${options[$(($option-1))]%.tar} ;; *) echo "invalid option" 1>&2 exit 1 esac
Read more

Redirect to a HTTPS version using .htaccess -

i need modify .htaccess file redirect urls https version without "www". http://example.com --> https://example.com http://www.example.com --> https://example.com https://www.example.com --> https://example.com this how .htaccess file looks like: rewriteengine on rewritecond %{request_filename} !-d rewritecond %{request_filename} !-f rewriterule ^(.*)$ redirect.php?id=$1&page=$2 [qsa,l] what modifications need make .htaccess in order forward https without "www"? it depends on doing current code. looks file called redirect trying display php page seo friendly url. think might confusing people. anyway, need , force https without www, need 1 more rule above. also second rule needs two capture groups in rewriterule test string because wanting 2 different values using $1 , $2 references. rewriteengine on #rediect www non www and/or http https --- combinations. rewritecond %{http_host} !^example\.com [nc,or] rewritecond %{https} !^...
Read more

javascript - jQuery: Add class depending on URL in the best way -

i have html progress meter: <div class="col-md-3" style="margin-left: -20px;"> <div class="progress-pos active" id="progess-1"> <div class="progress-pos-inner"> login </div> </div> </div> <div class="col-md-3 progress-pos-container"> <div class="progress-pos" id="progess-2"> <div class="progress-pos-inner"> scan items </div> </div> </div> <div class="col-md-3 progress-pos-container"> <div class="progress-pos" id="progess-3"> <div class="progress-pos-inner"> confirm address </div> </div> </div> <div class="col-md-3 progress-pos-container"> <div class="progress-pos" id="progess-4"> <div class="progress-pos-in...
Read more