writing

Data Intensive Systems: Lecture 1Why DBMSs exist and what they guarantee, schemas and data independence, the layered DBMS architecture, and conceptual design with the ER model: entities, relationships, constraints, weak entities, ISA hierarchies, and aggregation.Data Intensive Systems: Lecture 2The relational model and its algebra: tuples and instances, the key hierarchy, integrity constraints, SQL basics, the five basic operators, compound operators including join and division, and the query trees an optimizer rewrites.Data Intensive Systems: Lecture 3Storage and access: files, pages, and records, page and record layouts, row vs column stores, file organizations and their cost, indexing (dense, sparse, clustered, secondary, multilevel, composite), and index selection.Data Intensive Systems: Lecture 4The memory hierarchy and storage hardware: disk geometry and access time, flash and the FTL, RAID levels, disk space management, the buffer pool and page table, and replacement policies including Clock, LRU-K/2Q, and sequential flooding.Data Intensive Systems: Lecture 5B+ trees in depth: node structure and fan-out, search, insertion with leaf and internal splits, deletion with redistribution and merging, range scans over clustered vs unclustered data, and latch crabbing.Data Intensive Systems: Lecture 6Hashing and sorting for data systems: static and dynamic hashing (chained, extendible, linear), open addressing with linear probing, and external merge sort.Data Intensive Systems: Lecture 7Query processing with relational operators: physical plans, iterator and materialization models, access paths, selections, projections, and join algorithm costs.Data Intensive Systems: SQLSQL as a query language: vocabulary, single- and multi-table queries mapped onto relational algebra, the conceptual evaluation order, aggregation, grouping, and HAVING.Theory of Computation: Lecture 1Strings and languages, deterministic finite automata, state meanings, the state-characterization recipe for correctness proofs, and the first closure constructions.Theory of Computation: Lecture 2Nondeterminism, NFAs and their acceptance, the subset construction with its equivalence proof, epsilon closure, and closure under concatenation.Theory of Computation: Lecture 3Non-regular languages, the pigeonhole argument, the pumping lemma as an adversary game, closure-based reductions, and a regular surprise.