def no_index_eq(db):
with open(db, "rb") as fd:
# read db root
page_size, usable_size, free_list_page, num_free_list_page = util.read_db_header(
fd)
fd.seek(100)
_, cell_pointer, _ = util.read_page_header(fd)
# read sqlite_master
# assume sqlite_master does not util.overflow
util.master_move_fd_to_record(fd, cell_pointer[0])
# 21 is size of 'TableEmployeeEmployee' NOTE: hardcode for now
fd.seek(21, 1)
table_root_page = util.read_to_int(fd, 1)
global header_page_read
header_page_read += 1
# equality search
print('Equality employee id 181162')
employee = search_table_child(fd, page_size, table_root_page,
usable_size, 'EMP_ID', 181162)
if employee:
print('Name: {} {} {}'.format(employee['First_Name'],
employee['Middle_Name'],
employee['Last_Name']))
else:
print('employee id 181162 not exist')
def no_index_range(db):
with open(db, "rb") as fd:
# read db root
page_size, usable_size, free_list_page, num_free_list_page = util.read_db_header(
fd)
fd.seek(100)
_, cell_pointer, _ = util.read_page_header(fd)
# read sqlite_master
# assume sqlite_master does not util.overflow
util.master_move_fd_to_record(fd, cell_pointer[0])
# 21 is size of 'TableEmployeeEmployee' NOTE: hardcode for now
fd.seek(21, 1)
table_root_page = util.read_to_int(fd, 1)
global header_page_read
header_page_read += 1
# range search
print('Range seach eid between 171800 and 171899')
for i in range(100):
eid = 171800 + i
employee = search_table_child(fd, page_size, table_root_page,
usable_size, 'EMP_ID', eid)
if employee:
print('EMP_ID: {}, Name: {} {} {}'.format(employee['EMP_ID'], \
employee['First_Name'], employee['Middle_Name'], employee['Last_Name']))
else:
print('employee id {} not exist'.format(eid))
def no_index_scan(db):
with open(db, "rb") as fd:
# read db root
page_size, usable_size, free_list_page, num_free_list_page = util.read_db_header(
fd)
fd.seek(100)
_, cell_pointer, _ = util.read_page_header(fd)
# read sqlite_master
# assume sqlite_master does not util.overflow
util.master_move_fd_to_record(fd, cell_pointer[0])
# 21 is size of 'TableEmployeeEmployee' NOTE: hardcode for now
fd.seek(21, 1)
table_root_page = util.read_to_int(fd, 1)
global header_page_read
header_page_read += 1
# scan
print('Scan Last name Rowe')
employee = search_table_child(fd, page_size, table_root_page,
usable_size, 'Last_Name', 'Rowe')
if employee:
print('EMP_ID: {}, Name: {} {} {}'.format(employee['EMP_ID'], \
employee['First_Name'], employee['Middle_Name'], employee['Last_Name']))
else:
print('No one has last name Rowe')
def with_index_with_rowid_range(db):
with open(db, "rb") as fd:
# read db root
page_size, usable_size, free_list_page, num_free_list_page = util.read_db_header(
fd)
fd.seek(100)
_, cell_pointer, _ = util.read_page_header(fd)
# read sqlite_master
# assume sqlite_master does not util.overflow
util.master_move_fd_to_record(fd, cell_pointer[0])
# 21 is size of 'TableEmployeeEmployee' NOTE: hardcode for now
fd.seek(21, 1)
table_root_page = util.read_to_int(fd, 1)
util.master_move_fd_to_record(fd, cell_pointer[1])
# 40 is size of 'indexsqlite_autoindex_Employee_1Employee' NOTE: hardcode for now
fd.seek(40, 1)
index_root_page = util.read_to_int(fd, 1)
global header_page_read
header_page_read += 1
# range search
print('Range seach eid between 171800 and 171899')
row_ids = search_range_index(fd, page_size, index_root_page, 171800,
171899)
for row_id in row_ids:
employee = search_equality_index(fd, page_size, table_root_page,
row_id)
print('EMP_ID: {}, Name: {} {} {}'.format(employee['EMP_ID'], \
employee['First_Name'], employee['Middle_Name'], employee['Last_Name']))