def main(cls, args):
# db = SimpleDB("tabletest", 400, 8)
fm = FileMgr(File("tabletest"), 400)
lm = LogMgr(fm, "simpledb.log")
bm = BufferMgr(fm, lm, 8)
tx = Transaction(fm, lm, bm)
tm = TableMgr(True, tx)
tcatLayout = tm.getLayout("tblcat", tx)
print("Here are all the tables and their lengths.")
ts = TableScan(tx, "tblcat", tcatLayout)
while ts.next():
tname = ts.getString("tblname")
slotsize = ts.getInt("slotsize")
print(tname + " " + str(slotsize))
ts.close()
print("\nHere are the fields for each table and their offsets")
fcatLayout = tm.getLayout("fldcat", tx)
ts = TableScan(tx, "fldcat", fcatLayout)
while ts.next():
tname = ts.getString("tblname")
fname = ts.getString("fldname")
offset = ts.getInt("offset")
print(tname + " " + fname + " " + str(offset))
ts.close()
def getViewDef(self, vname, tx):
result = None
layout = self.tblMgr.getLayout("viewcat", tx)
ts = TableScan(tx, "viewcat", layout)
while ts.next():
if ts.getString("viewname") == vname:
result = ts.getString("viewdef")
break
ts.close()
return result
def getIndexInfo(self, tblname, tx):
result = {}
ts = TableScan(tx, "idxcat", self.layout)
while ts.next():
if ts.getString("tablename") == tblname:
idxname = ts.getString("indexname")
fldname = ts.getString("fieldname")
tblLayout = self.tblmgr.getLayout(tblname, tx)
tblsi = self.statmgr.getStatInfo(tblname, tblLayout, tx)
ii = IndexInfo(idxname, fldname, tblLayout.schema(), tx, tblsi)
result[fldname] = ii
ts.close()
return result
def main(cls, args):
# db = SimpleDB("tabletest", 400, 8)
fm = FileMgr(File("tabletest"), 400)
lm = LogMgr(fm, "simpledb.log")
bm = BufferMgr(fm, lm, 8)
tx = Transaction(fm, lm, bm)
sch = Schema()
sch.addIntField("A")
sch.addStringField("B", 9)
layout = Layout(sch)
for fldname in layout.schema().fields():
offset = layout.offset(fldname)
print(fldname + " has offset " + str(offset))
print("Filling the table with 50 random records.")
ts = TableScan(tx, "T", layout)
for i in range(50):
ts.insert()
n = random.randint(0, 50)
ts.setInt("A", n)
ts.setString("B", "rec" + str(n))
print("inserting into slot " + ts.getRid().__str__() + ": {" +
str(n) + ", " + "rec" + str(n) + "}")
print("Deleting these records, whose A-values are less than 25.")
count = 0
ts.beforeFirst()
while ts.next():
a = ts.getInt("A")
b = ts.getString("B")
if a < 25:
count += 1
print("slot " + ts.getRid().__str__() + ": {" + str(a) + ", " +
b + "}")
ts.delete()
print(str(count) + " values under 10 were deleted.\n")
print("Here are the remaining records.")
ts.beforeFirst()
while ts.next():
a = ts.getInt("A")
b = ts.getString("B")
print("slot " + ts.getRid().__str__() + ": {" + str(a) + ", " + b +
"}")
ts.close()
tx.commit()
def getLayout(self, tblname, tx):
size = -1
tcat = TableScan(tx, "tblcat", self.tcatLayout)
while tcat.next():
if tcat.getString("tblname") == tblname:
size = tcat.getInt("slotsize")
break
tcat.close()
sch = Schema()
offsets = {}
fcat = TableScan(tx, "fldcat", self.fcatLayout)
while fcat.next():
if fcat.getString("tblname") == tblname:
fldname = fcat.getString("fldname")
fldtype = fcat.getInt("type")
fldlen = fcat.getInt("length")
offset = fcat.getInt("offset")
offsets[fldname] = offset
sch.addField(fldname, fldtype, fldlen)
fcat.close()
return Layout(sch, offsets, size)
def refreshStatistics(self, tx):
self.tablestats = {}
self.numcalls = 0
tcatlayout = self.tblMgr.getLayout("tblcat", tx)
tcat = TableScan(tx, "tblcat", tcatlayout)
while tcat.next():
tblname = tcat.getString("tblname")
layout = self.tblMgr.getLayout(tblname, tx)
self.lock.release()
si = self.calcTableStats(tblname, layout, tx)
self.lock.acquire()
self.tablestats[tblname] = si
tcat.close()