Three registers and a tie-out take one storage operator's extract from 417,620 raw rows to 413,896 in the AC570 data preparation log shown for Unit 3. Searches like "ac 570 unit 3 assignment example", "ac570 unit 3 sample" and "ac570 unit 3 example" land here.
What a finished AC570 Unit 3 data preparation log looks like
Three registers, then a reconciliation, across four pages. The exclusion register removes 1,318 rows duplicated where two quarterly exports overlapped on 30 September and 2,406 rows from a training facility where staff practice, leaving 413,896. The join register records three joins by key and match rate: the unit master matched every row but 212, of which 196 were recovered through a crosswalk from one facility's remodel and 16 stay flagged; the user table tagged 37 of 251 IDs as system accounts such as the online portal; the facility table added time zones and office hours. The transformation register converts stamps to local time for 20 Eastern and 11 Central facilities and flags 4,152 void pairs without deleting them. The tie-out follows on its own page.
How a AC570 Unit 3 example is structured
Exclusions run first because every later count depends on them, and each carries the rows removed, the rule and a sentence on how the problem was found. Joins come second, since a join can drop or multiply rows without warning; each entry states the key, the rows matched, the rows unmatched and what happened to them, so a silent loss would show up as arithmetic. Transformations follow, changing fields without changing row counts, and the log says so for each. Flags are preferred to deletion wherever a row might matter later: an original and its void net to zero, yet a pattern of voids is itself worth testing. System accounts are tagged and kept, because portal credits reduce revenue just as staff credits do. The tie-out closes the log against the general ledger.
Rows that leave, and why
1,318 duplicates from overlapping quarterly pulls and 2,406 practice entries from a training facility. Nothing else is removed, and the log records that restraint as a decision of its own.
Joins with match rates
Unit master, user table and facility calendar, each joined on a named key. Only the unit join fails to match fully: 212 rows, 196 recovered, 16 flagged.
Local time, date by date
Stamps shift four to six hours depending on zone and season, with daylight saving applied by transaction date rather than by one offset for the whole year.
Flags instead of deletions
4,152 void pairs and 37 system accounts stay in the file with markers, so later tests can include or exclude them and state which they did.
Tied to the ledger
Credits in the cleaned file total 1,547,885.05; the concessions account holds 1,546,887.68. One Facility 6 credit of 997.37, entered 31 December and swept into the ledger 2 January, explains the gap.
Where marks go in AC570 Unit 3
An AC570 preparation log is marked as evidence, so the heaviest penalty falls on a clean file whose route back to the raw extract cannot be followed. Joins recorded without match rates come close behind; a join that quietly drops unmatched rows changes every later figure and leaves no trace unless counts are written down. Ignoring time zones is a costly technical miss in this dataset, since it would load thousands of daytime credits into the timing test. Deleting void pairs or system-account rows as noise draws deductions, because both carry information later tests need. A tie-out with an unexplained difference, however small, undercuts the whole log. Entries stating what changed without the rule behind the change cost smaller amounts in most sections.
Get a AC570 Unit 3 example written to your instructions
Attach the extract from the Unit 3 assignment, or a column list if the file must stay inside your section, along with the brief and the rubric. The log, its registers and a tie-out to whatever control figure your data allows return within 24-48h, each entry repeatable from the raw file. No fee applies to a first custom sample.
AC570 Unit 3 questions, answered
Why keep void pairs instead of deleting them?
Because the pair nets to zero but the act of voiding carries information. A site where staff void and re-enter credits unusually often might be correcting honest errors or disguising something, and an exception test can only look if the rows survive. The AC570 sample flags each pair, excludes flagged rows from totals where they would double count, and says so in the register.
Does every join need a match rate?
In most AC570 sections, yes. A join is where rows vanish without any error message, so the count of matched and unmatched rows is the only evidence nothing was lost. Here the unit master missed 212 rows; 196 came back through a remodel crosswalk and 16 stayed flagged. If your join matches fully, the log should still record that it did.
What should the log tie out to?
A number produced outside the extract that the prepared file should match, most often a general ledger balance for the same period. The sample ties total credits to the concessions account and explains a 997.37 difference with one late-December entry. If your data offers no ledger figure, a source-system report total or the row count on an extraction receipt can serve, and the log names which one it used.