chore: recompile pdfs

cs3223/main.typ

@@ -2,11 +2,78 @@
 
 
 #show: ilm.with(
-  title: [],
+  title: [CS3223 Database System Implementation],
   author: "Yadunand Prem",
   table-of-contents: none,
 )
-#set text(lang: "en", font: ("SF Pro Condensed"))
+#set text(lang: "en", font: ("SF Pro Display"))
 #show raw: set text(font: "SF Mono")
 
-== Reference
+= Reference
+
+= Lecture 1
+- #link("/Users/yadunut/Documents/2 NUS/S7 CS3223/lect00-intro.pdf", "intro")
+- #link("/Users/yadunut/Documents/2 NUS/S7 CS3223/lect01-storage.pdf", "storage")
+== Disk Access Timings
+- Seek time: move arm to position disk head on track
+- rotation delay: wait to rotate under head
+- transfer time: time to read/write data
+
+== Storage Manager
+- You are reading / writing data in Blocks (aka pages)
+=== Buffer Manager
+- Buffer Pool - Main Memory allocated for DBMS, partitioned into pages called frames
+- Clients are the queryplanner, etc.
+  - Can request for disk page to be fetched to the buffer
+  - Can release a disk page to the buffer
+- Page is dirty if it has been modified & not written back to disk
+- Variables maintained for each frame
+  - Pin Count: Number of clients using the frame (initial: 0)
+  - dirty: Is the frame dirty? (initial: false)
+- Initial: All frames are free
+- When a client requests a page $p$:
+  - Is $p$ in frame $f$?
+    - If yes, increment pin count (aka *pinning*)
+    - If no, is free list empty?
+      - If no, move some frame $f'$ from free list to buffer pool, $"pin count" = 1$, read $p$ into $f'$, return address of frame $f$
+      - If yes, Pick frame $f'$ with pin count = 0 for replacement, set $"pin count" = 1$. Is dirty flag of f' = true?
+        - If yes, write page in $f'$ to disk
+        - read p into $f'$, return address of frame $f'$
+- Buffer Manager replacement policy
+  - Random
+  - FIFO: First In First Out
+  - MRU: Most Recently Used
+  - *LRU: Least Recently Used* - Most commonly used
+    - Temporal Locality - If a page is accessed, it is likely to be accessed again soon
+    - Spatial Locality - If a page is accessed, its neighbours are also likely to be accessed
+    - Built with a queue of pointers to frames with $"pin count" = 0$
+  - Clock: LRU Variant (aka 2nd Chance)
+    - Keep track of a referenced bit for each frame
+    - When frame's pin count is 0, check referenced bit
+      - If 0, replace frame
+      - If 1, set referenced bit to 0 and move to end of queue
+=== File
+- Abstraction
+  - Each relation is a file of records
+  - Each record is a tuple, with a RID (Record ID) or TID (Tuple ID) as a unique identifier
+  - CRUD operations on file
+- Organization: Method of arranging records in a file
+  - Heap: Unordered
+  - Sorted: Ordered on some search key
+  - Hashed: Records are located in blocks via hash fn
+
+==== Heap Impl
+- Linked list Impl
+  - Problem: FInding a data page requires a linear search, accessing $n$ pages takes $O(n)$ time
+- Page Directory Impl
+  - Directory of pages, where the directory stores whether the page is free or occupied (1 bit + pointer)
+  - 1 page can contain many directory entries. Searching for a page is much faster.
+  - Problem: If directory is in main memory, it can be accessed in $O(1)$ time, but if not, it takes $O(n)$ time to access
+==== Fix length Page Format
+- RID = (Page ID, Slot Number)
+- Packed organization: Store records in contiguous slots
+  - Invariant: All recors have to be contiguous
+  - Problem: If slot is deleted,
+    - the records needs to be shifted, which is expensive
+    - Not only that, the slot number changes, which requires updating all RIDs
+- Unpacked organization: Use bit array to maintain free slots

cs3231/main.typ

@@ -10,7 +10,7 @@
   // table-index: (enabled: true),
   // listing-index: (enabled: true),
 )
-#set text(lang: "en", font: ("SF Pro Condensed"))
+#set text(lang: "en", font: ("SF Pro Display"))
 #show raw: set text(font: "SF Mono")
 
 == Reference

cs4212/main.typ

@@ -6,7 +6,7 @@
   author: "Yadunand Prem",
   table-of-contents: none,
 )
-#set text(lang: "en", font: ("SF Pro Condensed"))
+#set text(lang: "en", font: ("SF Pro Display"))
 #show raw: set text(font: "SF Mono")
 
 == Reference

hsi2010/main.typ

@@ -0,0 +1,13 @@
+#import "@preview/ilm:1.4.1": *
+
+
+#show: ilm.with(
+  title: [],
+  author: "Yadunand Prem",
+  table-of-contents: none,
+)
+#set text(lang: "en", font: ("SF Pro Display"))
+#show raw: set text(font: "SF Mono")
+
+== Reference
+*bolded* and regular