zulip/zerver/lib/migrate.py

80 lines
2.3 KiB
Python

import re
import time
def timed_ddl(db, stmt):
print
print time.asctime()
print stmt
t = time.time()
db.execute(stmt)
delay = time.time() - t
print 'Took %.2fs' % (delay,)
def validate(sql_thingy):
# Do basic validation that table/col name is safe.
if not re.match('^[a-z][a-z\d_]+$', sql_thingy):
raise Exception('Invalid SQL object: %s' % (sql_thingy,))
def do_batch_update(db, table, cols, vals, batch_size=10000, sleep=0.1):
validate(table)
for col in cols:
validate(col)
stmt = '''
UPDATE %s
SET (%s) = (%s)
WHERE id >= %%s AND id < %%s
''' % (table, ', '.join(cols), ', '.join(['%s'] * len(cols)))
print stmt
(min_id, max_id) = db.execute("SELECT MIN(id), MAX(id) FROM %s" % (table,))[0]
if min_id is None:
return
print "%s rows need updating" % (max_id - min_id,)
while min_id <= max_id:
lower = min_id
upper = min_id + batch_size
print '%s about to update range [%s,%s)' % (time.asctime(), lower, upper)
db.start_transaction()
params = list(vals) + [lower, upper]
db.execute(stmt, params=params)
db.commit_transaction()
min_id = upper
time.sleep(sleep)
def add_bool_columns(db, table, cols):
validate(table)
for col in cols:
validate(col)
coltype = 'boolean'
val = 'false'
stmt = ('ALTER TABLE %s ' % (table,)) \
+ ', '.join(['ADD %s %s' % (col, coltype) for col in cols])
timed_ddl(db, stmt)
stmt = ('ALTER TABLE %s ' % (table,)) \
+ ', '.join(['ALTER %s SET DEFAULT %s' % (col, val) for col in cols])
timed_ddl(db, stmt)
vals = [val] * len(cols)
do_batch_update(db, table, cols, vals)
stmt = 'ANALYZE %s' % (table,)
timed_ddl(db, stmt)
stmt = ('ALTER TABLE %s ' % (table,)) \
+ ', '.join(['ALTER %s SET NOT NULL' % (col,) for col in cols])
timed_ddl(db, stmt)
def create_index_if_nonexistant(db, table, col, index):
validate(table)
validate(col)
validate(index)
test = """SELECT relname FROM pg_class
WHERE relname = %s"""
if len(db.execute(test, params=[index])) != 0:
print "Not creating index '%s' because it already exists" % (index,)
else:
stmt = "CREATE INDEX %s ON %s (%s)" % (index, table, col)
timed_ddl(db, stmt)