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DBT: Hard Mode Slide-Referenced Concepts (50x4 T/F)

Hard mode: for each of 50 prompts, evaluate four statements as True/False. Explanations cite exact PDF pages.

Learning path

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0 of 17 sections marked complete · about 126 minutes

Learning objectives

What you will be able to explain

  • Hard Mode: Which two locality types are highlighted as central for caching effectiveness?
  • Hard Mode: Which formula for cache-hit-ratio is shown in the storage lecture?
  • Hard Mode: What does the virtual-memory slide explicitly state?
  • Hard Mode: How are pages characterized in the data-layout lecture?
  • Hard Mode: In slotted pages, how is tupleID represented?
  • Hard Mode: What is a direct consequence of DSM/column layout mentioned in the slides?

Section 01

Hard Mode: Which two locality types are highlighted as central for caching effectiveness? to Hard Mode: What does the virtual-memory slide explicitly state?

01

Hard Mode: Which two locality types are highlighted as central for caching effectiveness?

The slide introduces temporal and spatial locality as the key access localities.

Source: 01_Storage.pdf, page 10. Hard mode note: each statement is evaluated independently

02

Hard Mode: Which formula for cache-hit-ratio is shown in the storage lecture?

The cache-hit-ratio is defined as nb_hits divided by total accesses (hits plus misses).

Source: 01_Storage.pdf, page 10. Hard mode note: each statement is evaluated independently

03

Hard Mode: What does the virtual-memory slide explicitly state?

The lecture states virtual memory can exceed physical memory and may page to disk.

Source: 01_Storage.pdf, page 20. Hard mode note: each statement is evaluated independently

Section 02

Hard Mode: How are pages characterized in the data-layout lecture? to Hard Mode: What is a direct consequence of DSM/column layout mentioned in the slides?

01

Hard Mode: How are pages characterized in the data-layout lecture?

Pages are described as fixed-sized blocks with a header and data portion.

Source: 02_Data_Layouts.pdf, page 10. Hard mode note: each statement is evaluated independently

02

Hard Mode: In slotted pages, how is tupleID represented?

The slotted-page structure explicitly shows tupleID = pageID + slotID.

Source: 02_Data_Layouts.pdf, page 11. Hard mode note: each statement is evaluated independently

03

Hard Mode: What is a direct consequence of DSM/column layout mentioned in the slides?

The column-layout slide states that column layout requires tuple reconstruction.

Source: 02_Data_Layouts.pdf, page 31. Hard mode note: each statement is evaluated independently

Section 03

Hard Mode: Which NSM/DSM/PAX comparison is consistent with the table in the lecture? to Hard Mode: How is CLOCK (Second Chance) characterized?

01

Hard Mode: Which NSM/DSM/PAX comparison is consistent with the table in the lecture?

The table lists inter-record spatial locality as No for NSM, Yes for DSM, Yes for PAX.

Source: 02_Data_Layouts.pdf, page 45. Hard mode note: each statement is evaluated independently

02

Hard Mode: Which policy is based on recency according to the eviction-policy slide?

LRU is described as eviction based on time/recency.

Source: 03_Caching.pdf, pages 20 and 22. Hard mode note: each statement is evaluated independently

03

Hard Mode: How is CLOCK (Second Chance) characterized?

The lecture explicitly says CLOCK improves over FIFO and approximates LRU with less overhead.

Source: 03_Caching.pdf, page 25. Hard mode note: each statement is evaluated independently

Section 04

Hard Mode: During CLOCK eviction search, what happens when a page with bit=1 is encountered? to Hard Mode: In indexing basics, when is an index usually most useful?

01

Hard Mode: During CLOCK eviction search, what happens when a page with bit=1 is encountered?

The algorithm states: if bit is 1, set it to 0 and continue; bit 0 is evicted.

Source: 03_Caching.pdf, page 26. Hard mode note: each statement is evaluated independently

02

Hard Mode: What is the key idea behind prefetching pages in the caching lecture?

Prefetching is described as loading data not needed yet but likely soon, often using sequential/asynchronous reads.

Source: 03_Caching.pdf, page 33. Hard mode note: each statement is evaluated independently

03

Hard Mode: In indexing basics, when is an index usually most useful?

The selectivity discussion shows index vs scan depends on expected result size; indexes are better for few qualifying tuples.

Source: 04_Indexing 1.pdf, page 8. Hard mode note: each statement is evaluated independently

Section 05

Hard Mode: What is a dense index? to Hard Mode: What is true for a secondary index in this lecture?

01

Hard Mode: What is a dense index?

Dense index is defined as one index entry per record/tuple.

Source: 04_Indexing 1.pdf, pages 12 and 14. Hard mode note: each statement is evaluated independently

02

Hard Mode: Which statement about sparse indexes is correct?

Sparse index is shown as a strict subset (often one per block) and useful when records are sorted.

Source: 04_Indexing 1.pdf, pages 12 and 16. Hard mode note: each statement is evaluated independently

03

Hard Mode: What is true for a secondary index in this lecture?

Secondary index is described as not determining data order; the slide states it can only be dense.

Source: 04_Indexing 1.pdf, page 23. Hard mode note: each statement is evaluated independently

Section 06

Hard Mode: Which balancing property is stated for B-trees? to Hard Mode: What can happen during B-tree insertion if there is no room?

01

Hard Mode: Which balancing property is stated for B-trees?

The lecture states B-trees are always balanced with equal root-to-leaf path length.

Source: 05_Indexing 2.pdf, page 12. Hard mode note: each statement is evaluated independently

02

Hard Mode: What design goal is emphasized for B-trees in DBMS?

B-trees are presented as designed for block-wise access; nodes are kept between half-full and full.

Source: 05_Indexing 2.pdf, page 12. Hard mode note: each statement is evaluated independently

03

Hard Mode: What can happen during B-tree insertion if there is no room?

Insertion without room triggers split; recursive propagation can reach root and increase tree height.

Source: 05_Indexing 2.pdf, page 29. Hard mode note: each statement is evaluated independently

Section 07

Hard Mode: Which deletion behavior is shown for B+-trees? to Hard Mode: Which two collision-handling strategies are explicitly listed?

01

Hard Mode: Which deletion behavior is shown for B+-trees?

The delete slide describes stealing keys from siblings or merging if stealing is not possible, with possible propagation.

Source: 05_Indexing 2.pdf, page 35. Hard mode note: each statement is evaluated independently

02

Hard Mode: What is the range of hash function output h(K) in the lecture’s basic model?

Hash output is defined as an integer between 0 and B-1, with B buckets.

Source: 06_Indexing 3_hash_tables.pdf, page 8. Hard mode note: each statement is evaluated independently

03

Hard Mode: Which two collision-handling strategies are explicitly listed?

The collision slide names separate chaining and open addressing as handling strategies.

Source: 06_Indexing 3_hash_tables.pdf, page 9. Hard mode note: each statement is evaluated independently

Section 08

Hard Mode: Why is dynamic resizing discussed for hash tables? to Hard Mode: Which set is shown as kinds of multidimensional indexes?

01

Hard Mode: Why is dynamic resizing discussed for hash tables?

The lecture motivates resizing due to fill/waste tradeoffs and notes full rehashing is costly.

Source: 06_Indexing 3_hash_tables.pdf, page 11. Hard mode note: each statement is evaluated independently

02

Hard Mode: Which dynamic hash-table families are covered in the lecture?

The static-vs-dynamic slide explicitly lists extensible hashing and linear hashing.

Source: 06_Indexing 3_hash_tables.pdf, page 20. Hard mode note: each statement is evaluated independently

03

Hard Mode: Which set is shown as kinds of multidimensional indexes?

The slide’s index-family overview lists these multidimensional structures.

Source: 07_1_Multidimensional Indexing.pdf, page 63. Hard mode note: each statement is evaluated independently

Section 09

Hard Mode: How are bitmap indexes described conceptually? to Hard Mode: How is point search explained for the grid file?

01

Hard Mode: How are bitmap indexes described conceptually?

The bitmap-index slide defines a bit vector per value showing whether it is present in each row.

Source: 07_1_Multidimensional Indexing.pdf, page 92. Hard mode note: each statement is evaluated independently

02

Hard Mode: What is the core construction idea of a grid file?

The grid-file idea slide states exactly this stripe-and-grid construction.

Source: 07_2_multidimensional indexing_pt2.pdf, page 2. Hard mode note: each statement is evaluated independently

03

Hard Mode: How is point search explained for the grid file?

The search slide describes determining per-dimension positions and mapping to a bucket, with overflow blocks permitted.

Source: 07_2_multidimensional indexing_pt2.pdf, page 3. Hard mode note: each statement is evaluated independently

Section 10

Hard Mode: Which statement matches the kd-tree slide? to Hard Mode: What is emphasized about logical vs. physical query operators?

01

Hard Mode: Which statement matches the kd-tree slide?

The kd-tree slide explicitly defines them as a BST generalization over k dimensions with attribute alternation.

Source: 07_2_multidimensional indexing_pt2.pdf, page 20. Hard mode note: each statement is evaluated independently

02

Hard Mode: For an R-tree point query, what is required when regions overlap?

The operations slide states that if a point is contained in multiple regions, descent must continue through all overlaps.

Source: 07_2_multidimensional indexing_pt2.pdf, page 40. Hard mode note: each statement is evaluated independently

03

Hard Mode: What is emphasized about logical vs. physical query operators?

The lecture gives hash join and sort-merge join as alternative physical implementations.

Source: 08_Query Execution.pdf, page 5. Hard mode note: each statement is evaluated independently

Section 11

Hard Mode: Which dimensions of processing models are listed in the query-execution lecture? to Hard Mode: What is the parser’s responsibility in query optimization?

01

Hard Mode: Which dimensions of processing models are listed in the query-execution lecture?

These three dimensions are explicitly listed on the processing-model slide.

Source: 08_Query Execution.pdf, page 10. Hard mode note: each statement is evaluated independently

02

Hard Mode: How is morsel-driven parallelism described?

The slide defines morsels (around 1000 tuples) and dynamic runtime dispatch to threads.

Source: 08_Query Execution.pdf, page 62. Hard mode note: each statement is evaluated independently

03

Hard Mode: What is the parser’s responsibility in query optimization?

Parser responsibilities shown are parse-tree construction and syntax checking.

Source: 09_Query_Optimization.pdf, page 8. Hard mode note: each statement is evaluated independently

Section 12

Hard Mode: Which is a preprocessing task (not parser-only)? to Hard Mode: What assumption is called out as strong when combining conjunctive selectivities?

01

Hard Mode: Which is a preprocessing task (not parser-only)?

Preprocessing includes semantic correctness checks like relation, attribute, and type validation.

Source: 09_Query_Optimization.pdf, page 11. Hard mode note: each statement is evaluated independently

02

Hard Mode: How is output cardinality linked to selectivity in the lecture?

The slide states output cardinality equals input cardinality multiplied by selectivity (filter factor).

Source: 09_Query_Optimization.pdf, page 26. Hard mode note: each statement is evaluated independently

03

Hard Mode: What assumption is called out as strong when combining conjunctive selectivities?

The conjunction slide notes multiplication of selectivities relies on an independence assumption and calls it strong.

Source: 09_Query_Optimization.pdf, page 29. Hard mode note: each statement is evaluated independently

Section 13

Hard Mode: What is the Selinger-style enhancement over plain DP in the slides? to Hard Mode: When is a schedule conflict-serializable?

01

Hard Mode: What is the Selinger-style enhancement over plain DP in the slides?

Selinger-style optimization keeps track of interesting orders beyond the single cheapest partial plan.

Source: 09_Query_Optimization.pdf, page 49. Hard mode note: each statement is evaluated independently

02

Hard Mode: What does 'serializable' mean in the concurrency lecture?

Serializable schedules are defined as producing the same result as a serial schedule; interleaving can still occur.

Source: 10_Concurrency Control.pdf, page 24. Hard mode note: each statement is evaluated independently

03

Hard Mode: When is a schedule conflict-serializable?

The lecture states conflict-serializable iff the precedence graph has no cycle.

Source: 10_Concurrency Control.pdf, page 36. Hard mode note: each statement is evaluated independently

Section 14

Hard Mode: What does 2PL guarantee, and what can still occur? to Hard Mode: What is true for READ COMMITTED according to the isolation-level slide?

01

Hard Mode: What does 2PL guarantee, and what can still occur?

2PL is presented as guaranteeing serializability, while deadlocks remain possible.

Source: 10_Concurrency Control.pdf, page 47. Hard mode note: each statement is evaluated independently

02

Hard Mode: Which statement correctly describes Strict 2PL in the slides?

Strict 2PL keeps exclusive locks until commit/abort acknowledgement and ensures recoverable schedules.

Source: 10_Concurrency Control.pdf, page 53. Hard mode note: each statement is evaluated independently

03

Hard Mode: What is true for READ COMMITTED according to the isolation-level slide?

READ COMMITTED disallows dirty reads but still allows fuzzy reads and phantoms.

Source: 10_Concurrency Control.pdf, page 70. Hard mode note: each statement is evaluated independently

Section 15

Hard Mode: What does the STEAL policy permit? to Hard Mode: Which WAL rule is stated for update logging?

01

Hard Mode: What does the STEAL policy permit?

STEAL allows writing dirty pages even for uncommitted transactions.

Source: 11_Recovery.pdf, page 7. Hard mode note: each statement is evaluated independently

02

Hard Mode: Which method/policy pairing is shown in the recovery overview?

The overview slide pairs shadow paging with FORCE + NO-STEAL and WAL with NO-FORCE + STEAL.

Source: 11_Recovery.pdf, page 10. Hard mode note: each statement is evaluated independently

03

Hard Mode: Which WAL rule is stated for update logging?

WAL requires forcing update log records before writing the affected data page; commit also requires log durability.

Source: 11_Recovery.pdf, page 16. Hard mode note: each statement is evaluated independently

Section 16

Hard Mode: What is the three-pass recovery order shown in the lecture? to Hard Mode: What characterizes a homogeneous distributed database in the lecture?

01

Hard Mode: What is the three-pass recovery order shown in the lecture?

The recovery process is shown as Analysis pass, then Redo pass, then Undo pass.

Source: 11_Recovery.pdf, page 24. Hard mode note: each statement is evaluated independently

02

Hard Mode: How is speedup defined in the parallel-databases lecture?

Speedup is defined as sequential runtime over parallel runtime on p nodes; linear speedup is the ideal.

Source: 12_Parallel_DBs_and_Big_data.pdf, page 7. Hard mode note: each statement is evaluated independently

03

Hard Mode: What characterizes a homogeneous distributed database in the lecture?

Homogeneous systems are described with identical software and cooperative behavior, appearing as one system to users.

Source: 12_Parallel_DBs_and_Big_data.pdf, page 15. Hard mode note: each statement is evaluated independently

Section 17

Hard Mode: Which mapping between parallelism mode and workload focus is stated? to Hard Mode: How are replication and fragmentation described for distributed storage?

01

Hard Mode: Which mapping between parallelism mode and workload focus is stated?

The slide frames inter-query parallelism as key for transactional scenarios and intra-query parallelism for analytical scenarios.

Source: 12_Parallel_DBs_and_Big_data.pdf, page 24. Hard mode note: each statement is evaluated independently

02

Hard Mode: How are replication and fragmentation described for distributed storage?

The lecture defines replication vs fragmentation and explicitly notes that both can be combined.

Source: 12_Parallel_DBs_and_Big_data.pdf, page 31. Hard mode note: each statement is evaluated independently

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