truncate

When do we use the DELETE command versus the TRUNCATE command? I am trying to find on the Internet but both commands delete the data; I can't tell the difference. DELETE FROM TABLE 1. DELETE is a DML Command. 2. DELETE statement is executed using a row lock, each row in the table is locked for deletion. 3. We can specify filters in where clause 4. It deletes specified data if where condition exists. 5. Delete activates a trigger because the operation are logged individually. 6. Slower than truncate because, it keeps logs. 7. Rollback is possible. 8. LIMIT clause can also be used to set a limit

I've been parsing through some log files and I've found that some of the lines are too long to display on one line so Terminal.app kindly wraps them onto the next line. However, I've been looking for a way to truncate a line after a certain number of characters so that Terminal doesn't wrap, making it much easier to spot patterns. I wrote a small Perl script to do this: #!/usr/bin/perl die("need max length\n") unless $#ARGV == 0; while (<STDIN>) { $_ = substr($_, 0, $ARGV[0]); chomp($_); print "$_\n"; } But I have a feeling that this functionality is probably built into some other tools (sed?)

I'm trying to build a blog app and the problem is when I use tag 'truncatewords_html' in my template to truncate posts longer than specified number of words, I need to link to complete post by some title like 'read more...' after truncation. So I should know that the post was truncated or not. P.S.: Is this a pythonic way to solve the problem? {% ifequal post.body|length post.body|truncatewords_html:max_words|length %} {{ post.body|safe }} {% else %} {{ post.body|truncatewords_html:max_words|safe }}<a href="{{ post.url}}">read more</a> {% endifequal %} This is pretty convoluted but django has

We have a table with a 150+ million records. We need to clear/delete all rows. Delete operation would take forever due to it writing to the t-logs and we cannot change our recovery model for the whole DB. We have tested the truncate table option. What we realized that truncate deallocates pages from the table, and if I am not wrong makes them available for reuse but doesn't shrink the db automatically. So, if we want to reduce the DB size, we really would need to do run the shrink db command after truncating the table. Is this normal procedure? Anything we need to be careful or aware about, or

The following database view truncates the date to the fiscal year (April 1st): CREATE OR REPLACE VIEW FISCAL_YEAR_VW AS SELECT CASE WHEN to_number(to_char(SYSDATE, 'MM')) < 4 THEN to_date('1-APR-'||to_char(add_months(SYSDATE, -12), 'YYYY'), 'dd-MON-yyyy') ELSE to_date('1-APR-'||to_char(SYSDATE, 'YYYY'), 'dd-MON-yyyy') END AS fiscal_year FROM dual; This allows us to calculate the current fiscal year based on today's date. How can this calculation be simplified or optimized? ADD_MONTHS(TRUNC(ADD_MONTHS(SYSDATE,-3),'YYYY'),3) Perhaps this... SELECT to_date('01/04/' || to_char(extract(YEAR FROM

I have a paragraph that I want truncated with the option of clicking "read more" and have it slide open with the rest of the content. The content is coming from a database field. Here's what I have for the truncate: <%= truncate(@major.glance, :length => 250, :omission => '... Read More')%> I can't seem to find a way to do this with data pulled from a database. I see a lot of examples using the full text with the text you want to hide in a separate div tag. But, since this content is coming from a database and is dynamic I can't find any information on how to do it. You can try the following

I have values being cut off and would like to display the full values. Sqlite3 -column -header locations.dbs " select n.namelist, f.state, t.state from names n left join locations l on l.id = n.id left join statenames f on f.st = l.st left join statenames t on t.st = l.stto where n.timing > 200601 and count(n.timing)<=15" Which gives me name From State To State ---------- ----------- ---------- Jack Connecticut Louisiana Jeff Danie New Hampshi New Hampsh The names are being truncated down to 10 characters or the length of the first row of data, whichever is longer. How can I stop this from

Hive 有两种方法删除指定parition的数据：truncate partition, drop parition 功能： 两者都用于删除数据，即将对应的partition的数据文件删除。 不同点： truncate 只删除数据文件，保存在mysql中的metadata不会被删除。 drop partition 只删除数据文件且删除在mysql中的metadata。 举例： 表food的结构: id bigint name string 数据文件,food.data： 1 banana 2 orange 3 apple 4 nutz 导入food.data后查询, select * from food: 输出： 1 banana 20151219 2 orange 20151219 3 apple 20151219 4 nutz 20151219 现在想给food添加一列price: ALTER TABLE food ADD COLUMNS (price int); 表结构变成: id bigint name string price int 并且把food.data对应位置多加一列： 1 banana 20 2 orange 30 3 apple 30 4 nutz 40 删除旧的数据(drop partition) TRUNCATE TABLE food PARTITION