Difference between revisions of "Relational and non-relational databases"
From Gridkaschool
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| + | <pre> |
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| + | create table dl_test (id integer); |
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| + | insert into dl_test values (1); |
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| + | insert into dl_test values (2); |
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| + | 1: |
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| + | |||
| + | begin transaction; |
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| + | 2: |
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| + | |||
| + | begin transaction; |
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| + | 1: |
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| + | |||
| + | update dl_test set id=100 where id=1; |
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| + | |||
| + | 2: |
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| + | update dl_test set id=200 where id=2; |
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| + | 1: |
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| + | update dl_test set id=2000 where id=2; |
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| + | 2: |
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| + | |||
| + | update dl_test set id=1000 where id=1; |
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| + | 1: |
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| + | |||
| + | commit; |
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| + | 2: |
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| + | |||
| + | commit; |
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| + | </pre> |
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<pre> |
<pre> |
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import sys |
import sys |
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Revision as of 15:38, 27 August 2013
create table dl_test (id integer); insert into dl_test values (1); insert into dl_test values (2); 1: begin transaction; 2: begin transaction; 1: update dl_test set id=100 where id=1; 2: update dl_test set id=200 where id=2; 1: update dl_test set id=2000 where id=2; 2: update dl_test set id=1000 where id=1; 1: commit; 2: commit;
import sys
import random
import uuid
import time
import psycopg2
NR_OF_ROWS = 1000000
# connect to the database and set transaction level to autocommit
p_con = psycopg2.connect('host=localhost user=student password=student dbname=student')
p_con.set_isolation_level(0) # 0 (AUTOCOMMIT), 1 (READ COMMIT), 3 (SERIALIZE)
# get cursor
p_cur = p_con.cursor()
# drop old tables if they exist, ignore otherwise
try: p_cur.execute("DROP TABLE large_table")
except: pass
# create table and enable transactions
p_cur.execute("CREATE TABLE large_table (l CHAR, s VARCHAR(255), n INTEGER)")
p_con.set_isolation_level(1)
# insert random data
time_start = time.time()
for i in xrange(NR_OF_ROWS):
p_cur.execute("INSERT INTO large_table VALUES ('%s', '%s', %i)" % (chr(random.randrange(65, 91)),
''.join([chr(random.randrange(65, 91)) for i in xrange(1,16)]),
random.randint(0,1000000)))
p_con.commit()
print 'insert', time.time()-time_start
# query plans
p_cur.execute("ANALYZE large_table")
p_cur.execute("EXPLAIN SELECT COUNT(*) FROM large_table")
for row in p_cur:
print row
p_cur.execute("EXPLAIN SELECT * FROM large_table")
for row in p_cur:
print row
p_cur.execute("EXPLAIN SELECT * FROM large_table WHERE l='A'")
for row in p_cur:
print row
p_cur.execute("EXPLAIN SELECT * FROM large_table WHERE s='ASDFGH'")
for row in p_cur:
print row
p_cur.execute("EXPLAIN SELECT * FROM large_table WHERE n=3")
for row in p_cur:
print row
p_cur.execute("EXPLAIN SELECT * FROM large_table WHERE l='A' AND n=3")
for row in p_cur:
print row
p_cur.execute("EXPLAIN SELECT * FROM large_table WHERE l='A' AND s='ASDF' AND n=3")
for row in p_cur:
print row
time_start = time.time()
p_cur.execute("CREATE INDEX idxu_large_table_lsn ON large_table(l, s, n)")
print 'index', time.time()-time_start
p_cur.execute("EXPLAIN SELECT COUNT(*) FROM large_table")
for row in p_cur:
print row
p_cur.execute("EXPLAIN SELECT * FROM large_table")
for row in p_cur:
print row
p_cur.execute("EXPLAIN SELECT * FROM large_table WHERE l='A'")
for row in p_cur:
print row
p_cur.execute("EXPLAIN SELECT * FROM large_table WHERE s='ASDFGH'")
for row in p_cur:
print row
p_cur.execute("EXPLAIN SELECT * FROM large_table WHERE n=3")
for row in p_cur:
print row
p_cur.execute("EXPLAIN SELECT * FROM large_table WHERE l='A' AND n=3")
for row in p_cur:
print row
p_cur.execute("EXPLAIN SELECT * FROM large_table WHERE l='A' AND s='ASDF' AND n=3")
for row in p_cur:
print row
# close everything
p_cur.close()
p_con.close()
import uuid
import time
import sqlite3
import MySQLdb
import MySQLdb.cursors
import psycopg2
NR_OF_ROWS = 1000000
# connect to the database and set transaction level to autocommit
s_con = sqlite3.connect(database='/tmp/student.db', isolation_level=None) # None, 'DEFERRED', 'IMMEDIATE', 'EXCLUSIVE'
m_con = MySQLdb.connect(host='localhost', user='student', passwd='student', db='student', cursorclass = MySQLdb.cursors.SSCursor)
m_con.autocommit(True) # True, False
p_con = psycopg2.connect('host=localhost user=student password=student dbname=student')
p_con.set_isolation_level(0) # 0 (AUTOCOMMIT), 1 (READ COMMIT), 3 (SERIALIZE)
# get cursor
s_cur = s_con.cursor()
m_cur = m_con.cursor()
p_cur = p_con.cursor()
# drop old tables if they exist, ignore otherwise
try: s_cur.execute("DROP TABLE large_table")
except: pass
try: m_cur.execute("DROP TABLE large_table")
except: pass
try: p_cur.execute("DROP TABLE large_table")
except: pass
# create table
s_cur.execute("CREATE TABLE large_table (id VARCHAR(255) PRIMARY KEY)")
m_cur.execute("CREATE TABLE large_table (id VARCHAR(255) PRIMARY KEY) Engine=InnoDB")
p_cur.execute("CREATE TABLE large_table (id VARCHAR(255) PRIMARY KEY)")
# insert lots of rows and measure
print 'sqlite:',
time_start = time.time()
for i in xrange(NR_OF_ROWS):
pass # YOUR CODE HERE, USE str(uuid.uuid4())
print time.time()-time_start
print 'mysql:',
time_start = time.time()
for i in xrange(NR_OF_ROWS):
pass # YOUR CODE HERE, USE str(uuid.uuid4())
print time.time()-time_start
print 'postgresql:',
time_start = time.time()
for i in xrange(NR_OF_ROWS):
pass # YOUR CODE HERE, USE str(uuid.uuid4())
print time.time()-time_start
# drop table
s_cur.execute("DROP TABLE large_table")
m_cur.execute("DROP TABLE large_table")
p_cur.execute("DROP TABLE large_table")
# close everything
s_cur.close()
m_cur.close()
p_cur.close()
s_con.close()
m_con.close()
p_con.close()
import sqlite3
import MySQLdb
import MySQLdb.cursors
import psycopg2
# connect to the database and set transaction level to autocommit
s_con = sqlite3.connect(database='/tmp/student.db', isolation_level=None) # None, 'DEFERRED', 'IMMEDIATE', 'EXCLUSIVE'
m_con = MySQLdb.connect(host='localhost', user='student', passwd='student', db='student', cursorclass = MySQLdb.cursors.SSCursor)
m_con.autocommit(True) # True, False
p_con = psycopg2.connect('host=localhost user=student password=student dbname=student')
p_con.set_isolation_level(0) # 0 (AUTOCOMMIT), 1 (READ COMMIT), 3 (SERIALIZE)
# get cursor
s_cur = s_con.cursor()
m_cur = m_con.cursor()
p_cur = p_con.cursor()
# drop old tables if they exist, ignore otherwise
try: s_cur.execute("DROP TABLE test_table")
except: pass
try: m_cur.execute("DROP TABLE test_table")
except: pass
try: p_cur.execute("DROP TABLE test_table")
except: pass
# create table
s_cur.execute("CREATE TABLE test_table (id INTEGER PRIMARY KEY, value VARCHAR(255))")
m_cur.execute("CREATE TABLE test_table (id INTEGER PRIMARY KEY, value VARCHAR(255)) Engine=InnoDB")
p_cur.execute("CREATE TABLE test_table (id INTEGER PRIMARY KEY, value VARCHAR(255))")
# insert data
s_cur.execute("INSERT INTO test_table(id, value) VALUES (0, 'my first value')")
s_cur.execute("INSERT INTO test_table(id, value) VALUES (0, 'my second value')")
s_cur.execute("INSERT INTO test_table(id, value) VALUES (0, 'my second value')")
m_cur.execute("INSERT INTO test_table(id, value) VALUES (0, 'my first value')")
m_cur.execute("INSERT INTO test_table(id, value) VALUES (0, 'my second value')")
m_cur.execute("INSERT INTO test_table(id, value) VALUES (0, 'my second value')")
p_cur.execute("INSERT INTO test_table(id, value) VALUES (0, 'my first value')")
p_cur.execute("INSERT INTO test_table(id, value) VALUES (0, 'my second value')")
p_cur.execute("INSERT INTO test_table(id, value) VALUES (0, 'my second value')")
# selecting data (everything)
print 'sqlite'
s_cur.execute("SELECT id, value FROM test_table")
print s_cur.fetchall()
print 'mysql'
m_cur.execute("SELECT id, value FROM test_table")
print m_cur.fetchall()
print 'postgresql'
p_cur.execute("SELECT id, value FROM test_table")
print p_cur.fetchall()
# selecting data (iteratively)
print 'sqlite'
s_cur.execute("SELECT id, value FROM test_table")
for row in s_cur:
print row
print 'mysql'
m_cur.execute("SELECT id, value FROM test_table")
for row in m_cur:
print row
print 'postgresql'
p_cur.execute("SELECT id, value FROM test_table")
for row in p_cur:
print row
# close everything
s_cur.close()
m_cur.close()
p_cur.close()
s_con.close()
m_con.close()
p_con.close()
import sqlite3
import MySQLdb
import psycopg2
s_con = sqlite3.connect(database='/home/username/student.db')
m_con = MySQLdb.connect(host='localhost', user='student', passwd='student', db='student')
p_con = psycopg2.connect('host=localhost user=student password=student dbname=student')
s_con.close()
m_con.close()
p_con.close()
CREATE TABLE test_table (id integer, name varchar(255));
Hosts:
ssh <username>@<host>.scc.kit.edu -p24
- gks-148
- gks-149
- gks-150
- gks-151
- gks-152
- gks-153
- gks-154
- gks-155
- gks-156
- gks-157
- gks-158
- gks-159
- gks-160
- gks-161
- gks-162
- gks-163
- gks-164
- gks-165
- gks-166
- gks-167
- gks-168
- gks-169
- gks-170
- gks-171
- gks-172
- gks-173
- gks-174
