/usr/bin/bulk_loader is in skytools 2.1.12-6.
This file is owned by root:root, with mode 0o755.
The actual contents of the file can be viewed below.
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"""Bulkloader for slow databases (Bizgres).
Idea is following:
- Script reads from queue a batch of urlencoded row changes.
Inserts/updates/deletes, maybe many per one row.
- It creates 3 lists: ins_list, upd_list, del_list.
If one row is changed several times, it keeps the latest.
- Lists are processed in followin way:
ins_list - COPY into main table
upd_list - COPY into temp table, UPDATE from there
del_list - COPY into temp table, DELETE from there
- One side-effect is that total order of how rows appear
changes, but per-row changes will be kept in order.
The speedup from the COPY will happen only if the batches are
large enough. So the ticks should happen only after couple
of minutes.
"""
import sys, os, pgq, skytools
from skytools import quote_ident, quote_fqident
## several methods for applying data
# update as update
METH_CORRECT = 0
# update as delete/copy
METH_DELETE = 1
# merge ins_list and upd_list, do delete/copy
METH_MERGED = 2
# no good method for temp table check before 8.2
USE_LONGLIVED_TEMP_TABLES = False
def find_dist_fields(curs, fqtbl):
if not skytools.exists_table(curs, "pg_catalog.mpp_distribution_policy"):
return []
schema, name = fqtbl.split('.')
q = "select a.attname"\
" from pg_class t, pg_namespace n, pg_attribute a,"\
" mpp_distribution_policy p"\
" where n.oid = t.relnamespace"\
" and p.localoid = t.oid"\
" and a.attrelid = t.oid"\
" and a.attnum = any(p.attrnums)"\
" and n.nspname = %s and t.relname = %s"
curs.execute(q, [schema, name])
res = []
for row in curs.fetchall():
res.append(row[0])
return res
def exists_temp_table(curs, tbl):
# correct way, works only on 8.2
q = "select 1 from pg_class where relname = %s and relnamespace = pg_my_temp_schema()"
# does not work with parallel case
#q = """
#select 1 from pg_class t, pg_namespace n
#where n.oid = t.relnamespace
# and pg_table_is_visible(t.oid)
# and has_schema_privilege(n.nspname, 'USAGE')
# and has_table_privilege(n.nspname || '.' || t.relname, 'SELECT')
# and substr(n.nspname, 1, 8) = 'pg_temp_'
# and t.relname = %s;
#"""
curs.execute(q, [tbl])
tmp = curs.fetchall()
return len(tmp) > 0
class TableCache:
"""Per-table data hander."""
def __init__(self, tbl):
"""Init per-batch table data cache."""
self.name = tbl
self.ev_list = []
self.pkey_map = {}
self.pkey_list = []
self.pkey_str = None
self.col_list = None
self.final_ins_list = []
self.final_upd_list = []
self.final_del_list = []
def add_event(self, ev):
"""Store new event."""
# op & data
ev.op = ev.ev_type[0]
ev.data = skytools.db_urldecode(ev.ev_data)
# get pkey column names
if self.pkey_str is None:
if len(ev.ev_type) > 2:
self.pkey_str = ev.ev_type.split(':')[1]
else:
self.pkey_str = ev.ev_extra2
if self.pkey_str:
self.pkey_list = self.pkey_str.split(',')
# get pkey value
if self.pkey_str:
pk_data = []
for k in self.pkey_list:
pk_data.append(ev.data[k])
ev.pk_data = tuple(pk_data)
elif ev.op == 'I':
# fake pkey, just to get them spread out
ev.pk_data = ev.id
else:
raise Exception('non-pk tables not supported: %s' % self.name)
# get full column list, detect added columns
if not self.col_list:
self.col_list = ev.data.keys()
elif self.col_list != ev.data.keys():
# ^ supposedly python guarantees same order in keys()
# find new columns
for c in ev.data.keys():
if c not in self.col_list:
for oldev in self.ev_list:
oldev.data[c] = None
self.col_list = ev.data.keys()
# add to list
self.ev_list.append(ev)
# keep all versions of row data
if ev.pk_data in self.pkey_map:
self.pkey_map[ev.pk_data].append(ev)
else:
self.pkey_map[ev.pk_data] = [ev]
def finish(self):
"""Got all data, prepare for insertion."""
del_list = []
ins_list = []
upd_list = []
for ev_list in self.pkey_map.values():
# rewrite list of I/U/D events to
# optional DELETE and optional INSERT/COPY command
exists_before = -1
exists_after = 1
for ev in ev_list:
if ev.op == "I":
if exists_before < 0:
exists_before = 0
exists_after = 1
elif ev.op == "U":
if exists_before < 0:
exists_before = 1
#exists_after = 1 # this shouldnt be needed
elif ev.op == "D":
if exists_before < 0:
exists_before = 1
exists_after = 0
else:
raise Exception('unknown event type: %s' % ev.op)
# skip short-lived rows
if exists_before == 0 and exists_after == 0:
continue
# take last event
ev = ev_list[-1]
# generate needed commands
if exists_before and exists_after:
upd_list.append(ev.data)
elif exists_before:
del_list.append(ev.data)
elif exists_after:
ins_list.append(ev.data)
# reorder cols
new_list = self.pkey_list[:]
for k in self.col_list:
if k not in self.pkey_list:
new_list.append(k)
self.col_list = new_list
self.final_ins_list = ins_list
self.final_upd_list = upd_list
self.final_del_list = del_list
class BulkLoader(pgq.SerialConsumer):
def __init__(self, args):
pgq.SerialConsumer.__init__(self, "bulk_loader", "src_db", "dst_db", args)
def reload(self):
pgq.SerialConsumer.reload(self)
self.load_method = self.cf.getint("load_method", METH_CORRECT)
if self.load_method not in (0,1,2):
raise Exception("bad load_method")
self.remap_tables = {}
for map in self.cf.getlist("remap_tables", ''):
tmp = map.split(':')
tbl = tmp[0].strip()
new = tmp[1].strip()
self.remap_tables[tbl] = new
def process_remote_batch(self, src_db, batch_id, ev_list, dst_db):
"""Content dispatcher."""
# add events to per-table caches
tables = {}
for ev in ev_list:
tbl = ev.extra1
if not tbl in tables:
tables[tbl] = TableCache(tbl)
cache = tables[tbl]
cache.add_event(ev)
ev.tag_done()
# then process them
for tbl, cache in tables.items():
cache.finish()
self.process_one_table(dst_db, tbl, cache)
def process_one_table(self, dst_db, tbl, cache):
del_list = cache.final_del_list
ins_list = cache.final_ins_list
upd_list = cache.final_upd_list
col_list = cache.col_list
real_update_count = len(upd_list)
self.log.debug("process_one_table: %s (I/U/D = %d/%d/%d)" % (
tbl, len(ins_list), len(upd_list), len(del_list)))
if tbl in self.remap_tables:
old = tbl
tbl = self.remap_tables[tbl]
self.log.debug("Redirect %s to %s" % (old, tbl))
# hack to unbroke stuff
if self.load_method == METH_MERGED:
upd_list += ins_list
ins_list = []
# check if interesting table
curs = dst_db.cursor()
if not skytools.exists_table(curs, tbl):
self.log.warning("Ignoring events for table: %s" % tbl)
return
# fetch distribution fields
dist_fields = find_dist_fields(curs, tbl)
extra_fields = []
for fld in dist_fields:
if fld not in cache.pkey_list:
extra_fields.append(fld)
self.log.debug("PKey fields: %s Extra fields: %s" % (
",".join(cache.pkey_list), ",".join(extra_fields)))
# create temp table
temp = self.create_temp_table(curs, tbl)
# where expr must have pkey and dist fields
klist = []
for pk in cache.pkey_list + extra_fields:
exp = "%s.%s = %s.%s" % (quote_fqident(tbl), quote_ident(pk),
quote_fqident(temp), quote_ident(pk))
klist.append(exp)
whe_expr = " and ".join(klist)
# create del sql
del_sql = "delete from only %s using %s where %s" % (
quote_fqident(tbl), quote_fqident(temp), whe_expr)
# create update sql
slist = []
key_fields = cache.pkey_list + extra_fields
for col in cache.col_list:
if col not in key_fields:
exp = "%s = %s.%s" % (quote_ident(col), quote_fqident(temp), quote_ident(col))
slist.append(exp)
upd_sql = "update only %s set %s from %s where %s" % (
quote_fqident(tbl), ", ".join(slist), quote_fqident(temp), whe_expr)
# insert sql
colstr = ",".join([quote_ident(c) for c in cache.col_list])
ins_sql = "insert into %s (%s) select %s from %s" % (
quote_fqident(tbl), colstr, colstr, quote_fqident(temp))
# process deleted rows
if len(del_list) > 0:
self.log.info("Deleting %d rows from %s" % (len(del_list), tbl))
# delete old rows
q = "truncate %s" % quote_fqident(temp)
self.log.debug(q)
curs.execute(q)
# copy rows
self.log.debug("COPY %d rows into %s" % (len(del_list), temp))
skytools.magic_insert(curs, temp, del_list, col_list)
# delete rows
self.log.debug(del_sql)
curs.execute(del_sql)
self.log.debug("%s - %d" % (curs.statusmessage, curs.rowcount))
self.log.debug(curs.statusmessage)
if len(del_list) != curs.rowcount:
self.log.warning("Delete mismatch: expected=%s updated=%d"
% (len(del_list), curs.rowcount))
# process updated rows
if len(upd_list) > 0:
self.log.info("Updating %d rows in %s" % (len(upd_list), tbl))
# delete old rows
q = "truncate %s" % quote_fqident(temp)
self.log.debug(q)
curs.execute(q)
# copy rows
self.log.debug("COPY %d rows into %s" % (len(upd_list), temp))
skytools.magic_insert(curs, temp, upd_list, col_list)
if self.load_method == METH_CORRECT:
# update main table
self.log.debug(upd_sql)
curs.execute(upd_sql)
self.log.debug(curs.statusmessage)
# check count
if len(upd_list) != curs.rowcount:
self.log.warning("Update mismatch: expected=%s updated=%d"
% (len(upd_list), curs.rowcount))
else:
# delete from main table
self.log.debug(del_sql)
curs.execute(del_sql)
self.log.debug(curs.statusmessage)
# check count
if real_update_count != curs.rowcount:
self.log.warning("Update mismatch: expected=%s deleted=%d"
% (real_update_count, curs.rowcount))
# insert into main table
if 0:
# does not work due bizgres bug
self.log.debug(ins_sql)
curs.execute(ins_sql)
self.log.debug(curs.statusmessage)
else:
# copy again, into main table
self.log.debug("COPY %d rows into %s" % (len(upd_list), tbl))
skytools.magic_insert(curs, tbl, upd_list, col_list)
# process new rows
if len(ins_list) > 0:
self.log.info("Inserting %d rows into %s" % (len(ins_list), tbl))
skytools.magic_insert(curs, tbl, ins_list, col_list)
# delete remaining rows
if USE_LONGLIVED_TEMP_TABLES:
q = "truncate %s" % quote_fqident(temp)
else:
# fscking problems with long-lived temp tables
q = "drop table %s" % quote_fqident(temp)
self.log.debug(q)
curs.execute(q)
def create_temp_table(self, curs, tbl):
# create temp table for loading
tempname = tbl.replace('.', '_') + "_loadertmp"
# check if exists
if USE_LONGLIVED_TEMP_TABLES:
if exists_temp_table(curs, tempname):
self.log.debug("Using existing temp table %s" % tempname)
return tempname
# bizgres crashes on delete rows
arg = "on commit delete rows"
arg = "on commit preserve rows"
# create temp table for loading
q = "create temp table %s (like %s) %s" % (
quote_fqident(tempname), quote_fqident(tbl), arg)
self.log.debug("Creating temp table: %s" % q)
curs.execute(q)
return tempname
if __name__ == '__main__':
script = BulkLoader(sys.argv[1:])
script.start()
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